Ostia from Antiquity to Today

By Dr. Jan Theo Bakker / 05.05.2000
Professor of Archaeology
Leiden University

The ancient Roman city of Ostia was in antiquity situated at the mouth of the river Tiber, some 30 kilometres to the west of Rome. The shoreline moved seawards, due to silting, from the Middle Ages until the 19th century. Therefore Ostia is today still lying next to the Tiber, but at a distance of some three kilometers from the beach. Ostia is Latin for “mouth”, the mouth of the Tiber. The river was used as harbour, but in the Imperial period two harbour basins were added to the north, near Leonardo da Vinci airport. The harbour district was called Portus, Latin for “harbour”.

Early Ostia

The Earliest Ostia: 1400-400 BCE

Main changes of the Tiber river mouth location during the strand-plain evolution. Modified from Bellotti et al. 2011.

To the east of Ostia were salt-pans, where salt was probably already extracted in the Middle and Late Bronze Age (1400-1000 BC). There may have been a small village near the salt-pans in the Early Iron Age (1000-700 BC).

Three recent articles (2010-2011) form a breakthrough in the knowledge of the Holocene history of the coastal area of Rome [1]. Data were mainly collected from drillings, which were then interpreted from the sedimentological and paleobotanical viewpoint. Several phases of coastline advance were distinguished (see figure below). In the pollen diagram of the Lagoon of Ostia, an environment with marshy reeds and sedges with stagnant pools is recorded from about 3900 to 2600 years ago, a period characterized by geological and ecological instability associated with the migration of the cusp of the Tiber delta. The possibility of a temporary presence of the Tiber outlet in the area of the future imperial harbours (figure, 1st phase), before its migration to the present course alongside Ostia, is now generally accepted, and has found confirmation in several stratigraphic drilling data. It results also clearly from the study of the directions of the coastal barriers. This abrupt shifting to the south (2nd phase) has probably occurred in the seventh or eighth century B.C., in occasion of a heavy flooding.

According to ancient tradition (authors such as Ennius, Livius, Cicero and Dionysius of Halicarnassus) Ostia was founded by the fourth king of Rome, Ancus Marcius, who was thought to have ruled in the late seventh century BC. Even the year is mentioned: 620 BC [2]. So far no archaeological remains have been found in or near Ostia dating from this period. If a settlement existed, then it must have been a small outpost, not even a village. The existence of the settlement is likely, because Livius mentions Ostia twice in his accounts of the fifth century. Livy mentions floods of the Tiber in 414 and 363 BC (AUC 4.49.2-3 and 7.3.2).

New historical environmental data confirm that the original foundation of Ostia could have been on an ephemeral dune belt:
– Around 2600 years ago the Ostia marsh is affected by a sudden environmental change through the input of sea water, which transforms the basin from lacustrine to brackish. This transformation coincides chronologically with the foundation of Ostia. We don’t know if the sudden change was natural or due to human influence. Anyway, the width of the dune belt was too small too accommodate a real city, as Ostia was later to become. The hypothesis is that, at the time, it was only an outpost.
– The cuspate delta advanced seaward very quickly, at an estimated progradation rate of 5-6 metres per year, so that by the fifth to fourth century BC it was almost fully developed. By then, the dune belt was wide enough to allow the expansion of the city of Ostia.

The old road running from the north-west (mouth of the river Tiber) to the south-east. The north-west part of the road was called Via della Foce (“Road of the Mouth”) by the excavators. On the plan it is also called Via Laurentina, a road leading to the south-east to the village Laurentum. The Via Ostiense led to Rome.  The rectangle is a military fortress that was built later, probably in the early third century (see below). To the south of the fortress the old road continues (“southern stretch of the Cardo”).  Zevi 2001(2), fig. 1.

In Ostia the course of a very old road can still be traced. The road started at the mouth of the Tiber, and continued towards the south-east. It may belong to the sixth or fifth century BC. Today the first part of this road is called Via della Foce (“Road of the Mouth”), the second part “southern stretch of the Cardo”. This road would eventually lead to a great irregularity in the lay-out of Imperial Ostia.

The Castrum: 400-267 BCE

The remains of the Castrum projected on later buildings. This rectangular fortress, from the early third century BC, was built with large tufa blocks. Remains of these old walls can still be seen in a few places. The course of several streets in the centre of Imperial Ostia was determined by the lay-out of the fortress.

The oldest settlement that has been found is the so-called Castrum. It was a rectangular, military fortress (194 x 125.7 metres), with walls of large tufa blocks. Remains of the walls have been found around the later Forum. The two main streets, leading to four gates, were called Cardo and Decumanus. Historical events indicate, that the Castrum must have been built between 396 and 267 BC. Most modern historians have suggested that it was erected in either 349/8 or 338 BC, a period when Rome had to battle pirates and was at war with its neighbours. The oldest pottery from the Castrum has been dated to the period 380-340 BC.

More recently other proposals have been made. According to Filippo Coarelli the fortress is as old as the late fifth century BC, in view of the origin of the tufa (from Fidenae). According to Archer Martin it has to be dated to 300-275 BC, because pottery found next to the foundation of the walls belongs to that period. The older pottery (380-340 BC) could be the remains of votive offerings from an older temple (curiously isolated, however). Fausto Zevi has suggested the year 311 BC, when two duumviri navales, officials in charge of ships, were appointed. But they may also have been active in the harbour district in Rome itself.

The Capitolium (temple of Jupiter, Juno and Minerva) at the north end of the Forum, in the centre of Ostia. The present building dates back to the second century AD, and replaces two Augustan temples. The Imperial Forum is in the middle of the Castrum, but it is not known when the square was laid out.

The most solid evidence points to the date proposed by Archer Martin. Demetrius Waarsenburg suggests that, in view of historical events, the Castrum belongs to the period 292/1 BC (when the god Aesculapius was taken to Rome, but Ostia is not mentioned) to 278 BC (when a Carthaginian fleet reached Ostia). He thinks that the founding was mentioned in book XI of Livius, that has not been handed down to us.

The Late Republican Period: 267 BCE-Octavianius

Fragments of an inscription from the Imperial period, found in Ostia:

A[nco —]
Mar[cio —]
re[gi —]
quarto [a R]omul[o —]
qui ab urb[e c]ondit[a —]
[pri]mum colon[iam —]
[—] dedux[it —]

The Ostians, like many ancient authors, claimed that the city was founded as a colony by king Ancus Marcius.  Zevi 2001(1), fig. 1.

In the third century BC Ostia was primarily a naval base. In 267 BC it became the seat of one of the quaestores classici (officials taking care of the fleet), the quaestor Ostiensis. The office was related to the Punic wars, with Carthago. Ostia now played an important role as military harbour, and for that reason the inhabitants were freed from military duties, so that they could remain at work in the harbour.

In the second century BC Ostia gradually changed to a commercial harbour. The population of the city of Rome was growing after military successes. Grain was imported from Sicily and Sardinia, later also from Africa, that became a province in 146 BC. The quaestor now supervised the import of grain. The responsabilities made the office unpopular. In 104 BC it was held by Saturninus, who was replaced by M. Aemilius Scaurus. In the second or early first century BC the north-east part of Ostia, along the Tiber, was marked as public ground (i.e. reserved for Rome) by C. Caninius, praetor urbanus (i.e. from Rome). Little is known about the settlement in this period, because Ostia was almost entirely rebuilt in the second century AD. There must have been many shops, where food and beverages were sold, necessary for the voyage from Ostia to other harbours.

In 87 BC, during the civil war between the Sullans and Marians, the city was occupied and plundered by Marius. In 69/8 BC the city was plundered again, this time by pirates, who also destroyed a fleet in the river harbour. Not long afterwards Pompeius dealt with these pirates. It is probably the latter invasion that led to the building of new town walls by M. Tullius Cicero, in 63 BC. The work was finished in 58 BC by P. Clodius Pulcher, a political rival of Cicero. The new walls enclosed a much larger area.

Until the first century BC Ostia was governed from Rome, but from now on (possibly from the time of the building of the new walls) Ostia had its own government. The oldest fragment of the town records (fasti) is dated to 49 BC, but it is clear that this is not the start of the list.

There is a complication here. Several ancient authors, beginning with Cicero, state that Ostia was founded by Ancus Marcius as a colony (colonia). Inscriptions from the Imperial period prove that Ostia was indeed a colony. It is strange however, that a very old Roman colony had been governed from Rome until the first century BC. Therefore Ingrid Pohl has suggested that the city became a colonia only in the first half of the first century BC. An ancient author, Festus, wrote: “They say that the city of Ostia at the mouth of the Tiber … was founded by Ancus Marcius; by this is meant either the city, or the colony that was founded later”. Apparently there were two traditions in antiquity:

– the city was founded by Ancus Marcius as a city, not as a colony;
– the city was founded by Ancus Marcius as a colony, that was refounded later.
There are reasons to believe that the latter tradition was invented or caused by Cicero, builder of the new town walls, the true founding father of the colony [3].

Important monuments from the first century BC are the Four Small Temples and the Temple of Hercules. These were built by members of the local aristocracy: P. Lucilius Gamala (four times duovir, i.e. “mayor”) and C. Cartilius Poplicola (eight times duovir). Gamala seems to have sided with Cicero. His career has to be dated to the years 90-60 BC, or 70-35 BC. Poplicola was a supporter of Octavianus, and together with Agrippa he ensured the loyalty of the harbour to the later Augustus. Gamala and Poplicola were honoured by the Ostians for military deeds, including the repelling of an attack by Sextus Pompeius (son of the Pompeius who had fought the pirates), during the civil war in the years 40-36 BC. The ties of these men with Rome were not an exception: in this period the leading families of Ostia were also influential in Rome.

The Early Imperial Period

From Ostia to Rome: In the lower left are Ostia and Portus, separated by the articial island (Isola Sacra). The Via Ostiensis – followed by an aqueduct – connects Ostia and Rome. The Via Portuensis led from Portus to Rome. Between the two roads the meandering Tiber can be seen. To the east and north of Ostia and Portus are salt-pans (salinae). Near the modern town Acilia, further to the east, several archaeological discoveries have been made. Meiggs 1973, fig. 1.

Augustus – Domitianus

Marcus Agrippa, right-hand man of Augustus, built a theatre in Ostia for approximately 3000 spectators, in the period 18-12 BC. The special status that Ostia now had can be deduced from the use of marble, that was still exceptional. Marble was also used for the decoration of the tomb of Agrippa’s collaborator Poplicola. It is not clear when the Forum, the central square, was laid out, but during the reign of Augustus, at the end of the first century BC, two temples were built at its north side, possibly a Capitolium and a Temple of Jupiter. An aqueduct was built. In the early first century AD a Temple of Rome and Augustus was built at the south side of the Forum, by Tiberius (14-37 AD). Claudius (41-54 AD) sent urban cohorts to Ostia to fight fires. During the reign of Vespasian (69-79 AD) the city wall was changed to an aqueduct, taking water to the southern part of the city. Under Domitian (81-96 AD) the level of Ostia was raised c. 1 metre whenever new buildings were erected, probably to protect them from Tiber floodings. During his reign or a little later the present meeting hall of the town council and the main basilica were built to the west of the Forum. The Jewish community in Ostia built a synagogue near the beach at the end of the first century.

In this period Ostia was ruled by a small number of “aristocratic” merchant families of free descent. They lived in atrium-houses near the centre of town. Few remains of these houses have been found, because they were razed to the ground in the first half of the second century AD, when the city was largely rebuilt. The attitude of these families was conservative. The members were not able to use the prosperity of the first century AD to get hold of offices in Rome, contrary to what we see in other cities in Italy.

In 23 BC Tiberius was quaestor Ostiensis, the first step in his career. In 44 AD Claudius withdrew the quaestor from Ostia, and created a new office, that of the procurator annonae (“procurator of the grain-supply”), who worked for the praefectus annonae (“prefect of the grain-supply”) in Rome, who had been introduced by Augustus in the period 8-14 AD [4]. The procurators belonged to the equestrian order. They were supported by clerks (tabularii, dispensatores, etc.). The local grain-supply (many citizens received free grain, as in Rome) seems to have been coordinated by the procurator annonae Ostiensis, an office held by Imperial freedmen.

Many officials, such as the governors of provinces, now departed from and arrived in Ostia. In 2 AD Lucius Caesar, grandson of Augustus, died in Massilia (Marseille). The body arrived in Ostia, and was carried through the city, accompanied by officials carrying torches.

Portus: The Harbour Basins Built by Claudius and Traianus

Ostia was essential for the supplying of Rome, and therefore for the Emperor. Imperial slaves and freedmen worked in the harbour. Eventually Ostia would became the main harbour of Rome, but this took some time. The reason for this was, that the shore-line near Ostia did not offer natural protection to ships. Small boats could sail up the Tiber to Rome. Large ships unloaded at the Tiber quays of Ostia, very large ships out at sea. For these large ships Ostia was a dangerous place.

In 42 AD Claudius – a frequent visitor of Ostia – started the construction of an artificial harbour, a few kilometres to the north of Ostia. A huge basin was dug out, protected by two curved moles and with a lighthouse. Channels connected the basin with the Tiber, and created an artificial island between Ostia and Portus, called Isola Sacra (“Sacred Island”) in late antiquity. The completion of the work was celebrated in 64 AD, during the reign of Nero. But already in 62 AD the harbour was in use: in that year 200 ships in the basin perished during a storm, perhaps a tsunami (in the same year Pompeii was struck by an earthquake). From now on Ostia was the main harbour of Rome for goods from the western half of the Empire. Puteoli, in the Bay of Naples, remained Rome’s “eastern” harbour.

Trajan built a second, hexagonal basin behind the basin of Claudius. The work was carried out in the years 106-113 AD, and included improvements of the Claudian harbour. From now on the grain fleet from Alexandria in Egypt sailed to Ostia instead of Puteoli. In the course of the second century Ostia and Portus became the main harbour of Rome for goods from the entire Empire.

The harbour district was controlled by an Imperial official, the procurator Portus Ostiensis, called procurator Portus Utriusque (“of both harbours”) after the construction of the second harbour basin. Specialized procurators were in charge of the import of grain, oil, lead, wine, marble etc.

Ostia’s Hey-Day: The Second Century and the Severan Dynasty

The Emperors and Ostia

The addition of the harbour district led to a building boom and great prosperity in Ostia. The overwhelming majority of the buildings that have been excavated was built in the first half of the second century, during the reign of Trajan, Hadrian, and Antoninus Pius. The prosperity lasted until the Severan period, that is the early third century.

When the work on Trajan’s harbour was finished, the builders turned their attention to Ostia and started rebuilding the city, supervised by Hadrian (how they were able to take over the properties of the local aristocracy remains a mystery). Hadrian was twice duovir of Ostia, and in an inscription he was honoured because he had “preserved and enlarged the colony with all his indulgence and liberality” (colonia conservata et aucta omni indulgentia et liberalitate eius). During his reign the north-east part of the city (including the area that had been reserved by C. Caninius) was rebuilt with a rectangular plan. Fire-fighters (vigiles) from Rome were stationed in new barracks in this area. A huge Capitolium was erected to the north of the Forum. Hadrian’s successor Antoninus Pius and Gavius Maximus, an official in Rome, donated large baths. Warships from Misenum, a military naval base, were stationed at Ostia. The sailors acted as police, and took governors and Emperors to the provinces. They were also in charge of the awnings of the Colosseum in Rome.

In the second half of the second century and in the Severan period building activity was restricted to repairs and modifications. Commodus enlarged the theatre and refounded the colony as Colonia Felix Commodiana (“Happy Colony of Commodus”). Septimius Severus improved a road along the beach, connecting the mouth of the Tiber and Terracina. Probably during the reign of Alexander Severus, the last Emperor of the Severan dynasty (222-235 AD), a large round temple was built to the west of the Forum. It resembles the Pantheon in Rome. Inscriptions testify to the existence of an Imperial palace in Ostia.

The Local Government

A striking feature of Ostia is the large number of baths. They are found throughout the city. Some are very large and had expensive decoration, others are more modest.

The most important magistrates were two duoviri. They were appointed for a period of one year, and gave their name to the year. They presided over the city council. They acted as judges, but could not pass sentence of death, which could only be done in Rome. Therefore the symbols of their power were not fasces (a bundle of rods and an axe), but bacilli (rods without an axe). The duoviri were supported by two aediles, who supervised the markets, the standard weights and measures, and public facilities. Finances were in the hands of two quaestores aerarii. The city treasure was stored in the basement of the Capitolium. In the second century a new official is found, the curator operum publicorum et aquarum, who oversaw public buildings and the water supply. From the period of Trajan the quaestor alimentorum took care of poor children.

The city council had 100 (later 110) members called decuriones. In order to be admitted one had to be freeborn (which was also true for the sons of freed slaves), at least 25 years old, and wealthy. The council itself chose new members. It was supported by secretaries (scribae), attendants (lictores), messengers (viatores), town criers (praecones), and public slaves and freedmen. The latter were organized in a guild. In the early imperial period the people could elect the duoviri, but by the beginning of the second century AD this was no longer the case. Elections had ceased, and the city council appointed the duoviri.

Religious offices also formed part of a public career (cursus honorum). Vulcanus was the protective deity of Ostia, and his main priest, the pontifex Volcani, had general control over all temples in the city. He was assisted by praetores and aediles. He may be compared with the pontifex maximus in Rome, an office that was always held by the Emperor. In Ostia this office was the summit of a political career. It was helt for life. Minor religious offices were the priesthood of Rome and Augustus (related to the temple to the south of the Forum), and the priesthood of a deified emperor.

Ostia also needed patrons, who could stand up for the interests of the city in Rome. The patroni who were elected were men who had been successful in Rome. If possible, men of Ostian descent were selected.

Trade and Commerce

Ostia and Portus were more than safe harbours and quays, they were also complete cities. Many goods for Rome were stored in horrea (store-buildings), and transported to Rome along the Tiber in tow-boats, pulled by oxen.

Various guilds (collegia) became increasingly important: associations of craftsmen and merchants, but also burial clubs. These guilds may not be compared with mediaeval guilds, if only because membership was not obligatory. They played a social and economical role, and when they became “bodies” (corpora) the members had to perform duties in the public interest. Both free and freed people could join the guilds, and no distinction was made.

The presidents of the guilds were called quinquennales. They held the office for a period of five years. The treasurers were called quaestores or curatores, the ordinary members formed the plebs. And like the colony, the guilds could have patrons. The largest guilds were those of the builders and shipbuilders (fabri tignuarii and fabri navales), with a total of c. 350 members.

The People

The Ostians sometimes used communal latrines, several of which have been found in Ostia. People sat next to each other on seats that had holes in the top (for obvious reasons) and in the front (for the insertion of a sponge on a stick). A channel with running water was in front of their feet.

Through immigration and the import of slaves the population rose to fifty thousand, including some seventeen thousand slaves. Most slaves were taken to Ostia from Egypt, the Middle East, and Turkey. Many must have been foundlings, but the breeding of slaves must also have been a profitable trade. Most families had at least one slave, and there were many Imperial slaves, working in the harbour and store-buildings. Many slaves were manual labourers, others were clerks and accountants. The most frequent slave-name is Felix: “Happy”.

In this period we witness a rise in society of the middle class, of traders and merchants, often not of Ostian origin. Some were free immigrants, others freedmen [5]. Especially people from North Africa started to play a dominant role, but France, Spain, Greece, Turkey, Syria and Egypt are also documented. We encounter these immigrants as procuratores annonae, in the city council, and involved in all phases of the grain-supply: as owners of ships transporting grain over sea and the Tiber (navicularii and codicarii), as grain merchants (mercatores frumentarii), and as grain weighers (mensores frumentarii).

Freedmen were often active in the trade of their patron. The guild of the Seviri Augustales, focusing on the cult of the Emperors, was entirely made up of freedmen. It resembles the trade guilds. And as magistri vici freedmen were in charge of the cult of the Lares Compitales, deities worshipped at crossroads.

Many people who worked in Portus lived in Ostia. They crossed the Tiber with ferries (there was no bridge) and walked to the harbour district. A large necropolis on the Isola Sacra, near Portus, shows that apartments were also built near the harbour basins. The famous physician Galenus lived in Ostia from 169 until 175 AD. He wrote: “All the doctors in these places (Ostia and Portus) are my friends, and both are populous centres”.

The Archaeological Remains

This website focuses on the archaeological remains of Imperial Ostia and Portus. In the Topographical Dictionary (including thematic pages) and in other sections the remains are presented:

  • Apartments buildings, with two or three upper floors
  • The so-called medianum-apartments, the habitations of the commercial middle class
  • Domus, the houses of the upper class
  • Hotels, brothels, bars and hundreds of shops
  • Baths and communal latrines
  • The seats of guilds
  • Workshops, such as bakeries and fulleries
  • Store buildings
  • Public buildings
  • Temples and little shrines, dedicated to traditional and oriental deities
  • Wall-paintings
  • Mosaics
  • Sculpture
  • Graffiti

During its hey-day Ostia was a densily populated city, with a large variety of buildings, and a mixed and “international” population. But first and foremost it was a harbour city, serving the needs of Rome, characterized by store buildings (horrea) and the seats of commercial guilds. Ostia was much smaller than harbours such as Alexandria and Carthage. Not only was Ostia smaller, it was also more functional. Michael Heinzelmann has pointed out what was “missing” in Ostia. Only the north-east part of the city has a rectangular plan; the lay-out of the other districts remained irregular. The width of individual streets varies, apparently the result of the borders of private property. Porticos flanking the streets are found throughout the city, but identical porticos facing each other are exceptional. There were only a few squares. There was no amphitheater, no circus (Puteoli, formerly the main harbour of Rome, had a theater, two amphitheaters and a circus). The sudden commercial opportunities that arose after the construction of Trajan’s harbour were seized by entrepreneurs, who were interested in profit, not in developing Ostia’s infrastructure.

Decline, Late Antiquity, and Middle Ages

The Decline of Ostia

After the Severan dynasty there was political chaos in Rome. The reign of many Emperors was now ended by revolt or assassination after a few months or years. The economy collapsed. In Ostia building activity was minimal, and the number of inscriptions dropped dramatically. Old bricks and inscriptions were reused. The population shrunk. In the second half of the third and in the fourth century Ostia and Portus were struck by earthquakes and tsunamis. The first seem to have taken place in 238 AD (in Portus corpses were found below collapsed masonry), other evidence points to the reign of Probus (276-282 AD; several buildings collapsed), and an earthquake documented in Rome in 346 AD may also have damaged the harbours. Often the ruins were not even cleared. Apparently it was not economical to rebuild them [6]. The fire-brigade left Ostia in the second half of the third century: the horrea in Ostia were not used anymore (contrary to those in Portus). And other tensions were building up: in 269 AD eighteen Christians were executed in front of the theatre, on the main road (Decumanus).

The fasti were maintained until at least 175 AD. The last duovir is documented in 251 AD. Not much later Rome once more took over the control of Ostia and Portus. The city came under the authority of the prefect of the grain-supply (praefectus annonae), who was curator of the harbours. Together with Roman senators he governed Ostia and Portus. There were no local magistrates anymore. Imperial generosity focused on the area near the beach, not on the harbour district along the Tiber: Aurelian (270-275 AD) “began to construct a Forum, named after himself, in Ostia on the sea, in the place where, later, the public magistrates’ office was built”.

Late Antiquity

In 308/309 AD Maxentius moved the mint of Aquileia to Ostia, but this was a short-lived event. The mint was closed in 313 AD. Constantine made Portus an independent city, called Civitas Flavia Constantiniana. Portus had been and was growing at the expense of Ostia. The Alexandrian grain-fleet now took the Egyptian grain to Constantinople; Rome was supplied by Africa. On the other hand Constantine donated a Christian basilica to Ostia (discovered in the 1990’s by Michael Heinzelmann). And from 336 AD the bishop of Ostia consecrated the new pope. There are indications that the economy of Ostia was recovering in the fourth century. Many inscriptions from this period have been preserved, and the building activity increased, albeit with reused material (the marble slabs of the Fasti were used as thresholds).

A follis of Maxentius, from 309 AD. Struck in Ostia.
Obverse: IMP. C. MAXENTIVS P.F. AVG., and the laureate head of Maxentius.
Reverse: AETERNITAS AVG. N., Castor and Pollux holding their bridled horses, and M(oneta) OST. P.

But Ostia was from now on primarily a pleasant living environment. Many expensive habitations (domus) were built from the later third until the first quarter of the fifth century. These houses were probably owned by merchants who lived in Ostia and worked in Portus. In 387 AD S. Augustine stayed in Ostia with his mother Monica, who died there: “… she and I stood alone, leaning in a certain window, from which the garden of the house we occupied at Ostia could be seen; at which place, removed from the crowd, we were resting ourselves for the voyage (to Africa), after the fatigues of a long journey”. The area along the Tiber had been abandoned, and here rubble was dumped on the streets, to create a barrier (in places four metres high), to protect the southern part of the city from Tiber floodings. An inscription from the late fourth century mentions the transfer of a statue “from sordid places” (ex sordentibus locis).

In the early fifth century Ostia became an average Italian city, contrary to Portus, that remained important as harbour: from now on the praefectus annonae governed Portus, but not Ostia. In 410 AD Alaric with Goths, Huns and Alans sacked Rome. He also captured Portus, but ignored Ostia. In 455 AD Gaeseric and the Vandals sacked Portus. An inscription informs us that they burned the church of S. Hippolytus on the Isola Sacra. Perhaps they also plundered Ostia. At the end of the fifth century the Ostian aqueduct stopped functioning. Many Ostians now lived and were buried in ruins. At the same time Portus was a thriving harbour. In 537 Vitigis and the Goths laid siege to Portus. Belisarius defended Portus and Ostia. The last inhabitants of Roman Ostia had retreated to the theatre, that was turned into a little fortress.

The Middle Ages

In the early ninth century Ostia was captured by the Saracens. In response pope Gregory IV (827-844) built a new town to the east of Roman Ostia: Gregoriopolis, at the spot of the modern village Ostia Antica. Here the church of S. Aurea, a martyr from the third century AD, had been built. In the middle of the ninth century the Saracens returned, and took the fortress and Portus. Pope Nicholas I (858-867) reinforced the town. For a long time there had been marshes to the east of Ostia, in which rubble from Rome had been dumped after the great fire under Nero, in 64 AD. The marshes now became a lake, and the area was infested by malaria [7]. As late as 1162 AD the people of Gregoriopolis visited a little chapel near the theater, in a procession along the Via Ostiensis and Decumanus Maximus. But by now the tombs and buildings flanking the road were half-buried ruins.

From the Eleventh Century to the Present Day


In late antiquity the harbour district along the Tiber was deserted. The south part of town, near the beach, was fashionable. Luxurious mansions were built, decorated with marble and polychrome mosaics. Unfortunately, many marble objects (the decoration of walls and floors, statues, inscriptions) disappeared in lime kilns during the Middle Ages.

From the eleventh to the fourteenth century Ostian marble was reused in the cathedrals of Pisa, Florence, Amalfi and Orvieto. A document from 1191 mentions a spot in Ostia called calcaria. This is a reference to a lime-kiln, in which marble (floors, statues etc.) was burned to be used as mortar. Several lime-kilns have been excavated. The search for marble was easy, because Ostia was not entirely buried. Richard Coeur de Lion landed at the mouth of the Tiber and saw “immense ruins of ancient walls” (August 26, 1190).

In the fifteenth century the castle of Gregoriopolis was rebuilt by cardinal Giuliano della Rovere (this is the present castle). It had to protect Rome from incursions by raiders. In 1557 there was a major inundation. The meandering Tiber changed its course. The branch of the Tiber along the castle was cut off, so that the castle became useless. The old branch is now filled with earth and known as Fiume Morto (“Dead River”). The inundation of 1557 also destroyed a large stretch of the ancient Tiber quays.

From the fifteenth to eighteenth century promising ruins were searched by foreign visitors for inscriptions and statues. These ended up in private collections in England, France, Portugal, Spain and Russia (now mostly in national museums).

The random searching of the ruins was forbidden by Carlo Fea, director general of antiquities, in the early nineteenth century. The first excavations, initiated by pope Pius VII (Ostia belonged to the Vatican), were carried out by Petrini in the years 1801-1805. Between 1824 and 1834 there was a renewed hunt for treasure, and the objects that were found can today be seen in several countries, even in the USA. More or less structural activities began once more in 1855, under the auspices of pope Pius IX. The excavators were Pietro Ercole and Carlo Ludovico Visconti. They too focused on inscriptions, statues, mosaics, and paintings, that were taken to the Vatican and Lateran museums. Sometimes marble and granite were taken to Rome as building material. The present museum was built. Wealthy foreigners now started to visit Ostia as tourists. The site was reached with some difficulty with carriages (a railway was opened in 1924).

From 1870 Ostia was no longer a papal domain, but owned by the new Italian state. The excavations were continued by Pietro Rosa and Rodolfo Lanciani. In 1887 Dessau published the Ostian inscriptions in the Corpus Inscriptionum Latinarum (CIL) XIV.

Ostia is threatened by nature and people. In the 1980’s the capitals of the Basilica Cristiana were stolen. One day the building’s columns were standing upright with their capitals, the next day they had been pulled down, and the capitals had disappeared. For this reason many statues have been replaced by plaster copies. But even these are sometimes damaged by hooligans.

Truly scientific research started in 1907 by Dante Vaglieri. The north-east part of the city was now excavated systematically. Vaglieri died in 1913. The year before, the first monograph about Ostia had been published: “Ostia, Colonia Romana”, by Ludovico Paschetto. Important work was also done by the French archaeologist Jerome Carcopino.

Vaglieri was succeeded by Guido Calza, who was supported by architect Italo Gismondi and inspector Raffaele Finelli. Slowly more ruins were unearthed. In 1930 a supplement to the CIL appeared. In 1938 one-third of the city had been excavated. But then extensive, hurried excavations began, lasting until 1942. The initiator was Mussolini, who wanted to present Ostia during a world-fair (Esposizione Universale di Roma (EUR)). The excavated area was more than doubled. More than 600.000 cubic metres of earth were removed, that reached a height of 4 to 12 metres above the ancient street level. Needless to say that much information was not recorded during these five years. The world-fair never took place. Calza died in 1946.

After the Second World War the series “Scavi di Ostia” was published. Excavations continued on a very small scale. In 1960 a monumental, historical study about Ostia was published: “Roman Ostia”, by Russell Meiggs (second edition 1973). A detailed archaeological guide, written by Carlo Pavolini, was published in 1983. Excellent studies were written by Fausto Zevi. The on-line Ostia bibliography contained c. 1800 titles in 2003. Recently geophysical research by the German Archaeological Institute and the American Academy in Rome (Michael Heinzelmann and Archer Martin) provided a wealth of information about the unexcavated area, and led to several important discoveries, such as that of Constantine’s Basilica, and of a small harbour in the north-west part of the city. Similar geophysical research also took place in Portus by the University of Southampton (Simon Keay). The final publications of this research in Ostia and Portus will appear soon.

In Scavi di Ostia I the nomenclature of Ostian buildings was standardized. In antiquity Ostia was divided in five regions, but we do not know their borders. The excavators too divided the city in five regions, and furthermore in blocks (insulae) and buildings. An example of the numbering system is: Tempio d’Ercole (Temple of Hercules), I,XV,5 = building 5 in block 15 in region 1.

In the twentieth century many buildings have been restored. Visitors and students should be aware of this, but should not be too critical, because in most cases the modern craftsmen did a wonderful job.


Relatively few ruins have been excavated in Portus, partly because the area was private property of the Torlonia family. A fresco by A. Danti in the Vatican shows the ruins that could still be seen in 1582. Important descriptions were published by Carlo Fea and Antonio Nibby, in 1824 and 1829. Carlo Ludovico Visconti was in charge of excavations in the years 1864-1867, but all that was recorded were the statues that were found, and the ruins were covered with earth after the excavation. Rodolfo Lanciani published a description in 1868. Jerome Carcopino carried out excavations in 1907. Trajan’s basin was restored in 1923. In 1935 the first monograph appeared, written by Giuseppe Lugli.