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 somet hree kilometres 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. That harbour district was called Portus, Latin for "harbour".

Early Ostia

To the east of Ostia were salt-pans, where salt was probably already extracted in the Middle and Late Bronze Age (1400-1000 BC). According to ancient tradition Ostia was founded by the fourth king of Rome, Ancus Marcius, who was thought to have ruled in the late seventh century BC. This settlement was probably on a narrow dune belt and built when a meander of the Tiber reached the location of

Ostia for the first time, c. 700 BC. The oldest ruins that have been found in Ostia are those of the socalled Castrum. It was a rectangular, military fortress (194 x 125.7 metres), with walls of large tuff blocks. Remains of the walls have been found around the later Forum. The Castrum seems to have been built in the early third century 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. 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.

The early Imperial period

Under Domitian (81-96 AD) the level of Ostia was raised about one metre whenever new buildings were erected, probably to protect them from Tiber floods. In this period Ostia was ruled by a small number of "aristocratic" merchant families. They lived in 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. 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. After the death of Tiberius, Caligula took the ashes of his mother and brother to Rome, via Ostia. 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.

The harbour district In 42 AD Claudius - a frequent visitor of Ostia - started the construction of an artificial harbour, Portus, a few kilometres to the north of Ostia. A huge basin was dug out, protected by two curved moles and with a lighthouse. The lighthouse may have been 130 metres high. Channels connected the basin with the Tiber, and created an artificial island between Ostia and the harbour basins. The completion of the work was celebrated in 64 AD, during the reign of Nero. Trajan built a second, hexagonal basin behind the basin of Claudius. The work was carried out in the years 106-113 AD. The harbour district was controlled by an Imperial official. Specialized procurators were in charge of the import of grain, oil, lead, wine, marble, wild animals etcetera. Cranes must have been used for unloading heavy cargoes. Most of the harbour district has not yet been excavated.

The second century AD.

The addition of the harbour district led to a building boom and great prosperity in Ostia. Most of the buildings that have been excavated were 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.

In the second half of the second century and in the Severan period building activity was restricted to repairs and modifications. Commodus refounded the colony as Colonia Felix Commodiana ("Happy Colony of Commodus"), but that name was not used anymore after he was murdered. Ostia and Portus were more than safe harbours and quays, they were also complete cities. Many

goods for Rome were stored in store-buildings in the harbour cities and transported to Rome along the Tiber in tow-boats, pulled by oxen. Various guilds became increasingly important. These were 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.

The people Through immigration and the import of slaves the population rose to fifty thousand, including someseventeen 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". Freed slaves were often active in the trade of their patron. 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. Later, 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 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 cleared. Apparently

it was not economical to rebuild them. And other tensions were building up: in 269 AD eighteen Christians were executed in front of the theatre, on the main road (Decumanus). Constantine made Portus an independent city, called Civitas Flavia Constantiniana. Portus had been and was growing at the expense of Ostia. On the other hand Constantine donated a Christian basilica to Ostia and from 336 AD (until the present day) the bishop of Ostia consecrated the new pope.

Ostia in late antiquity

Ostia was from now on primarily a pleasant living environment. Many expensive habitations 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 Saint 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 floods. An inscription on the Forum, from the late fourth century, mentions the transfer of a statue "from sordid places" (ex sordentibus locis).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. Perhaps they also plundered Ostia. 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.

From the eleventh to the eighteenth century

Ostian marble was reused in the cathedrals of Pisa, Florence, Amalfi and Orvieto.