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The oldest traces of Ostia: From the Bronze Age to the foundation of the castrum

By Demetrius J. Waarsenburg

Hermeneus 70,2 (1998), 60-69

Below the imposing remains of Ostia a long history lies hidden. About the nature and dating a lot of disagreement exists, because up today there have been hardly any in-depth excavations in the city. The problem focuses primarily on two issues. The first concerns the foundation date of the castrum, the fort that was the core of the Republican colony. Historical sources do not mention the foundation, so that proposals for a date largely depend on the scarce archaeological finds from the castrum. The second issue is connected with the likely existence of a much older Ostia, well before the time of the castrum. About this the Roman historiography ís explicit. An extensive and unanimous tradition assigned the first foundation of Ostia to Ancus Marcius, the fourth king of Rome (640-616 BC). The problem is that to date no remains from the regal period have been found in Ostia to support the tradition.

Despite these limitations, the scientific discussion of the last years has produced many new perspectives about the oldest phases of Ostia, especially where it concerns the regal period (and earlier). In contrast, the dates assigned to the castrum are running ever further apart. This contribution provides an overview of the latest state of affairs and a new suggestion for the date of construction of the castrum.

The first foundation

The Romans did not doubt that king Ancus Marcius was the founder of Ostia. Eusebius in his Chronicon even mentions the precise date: in Ancus' twentieth year of government, i.e. in 620 BC. This tradition cannot be viewed separately from the presence of salt pans at the Tiber estuary and the great importance of salt in early Latin society. Salt was mainly used to preserve food and was therefore such an indispensable product that for a long time it was even used as a means of payment (compare salary from sal, salt). This fact considerably strengthens the credibility of the tradition.

In the 19th and the beginning of the 20th century, when it was customary to label all traditions from the regal period as fantasy, nevertheless major questions arose about the existence of a pre-Republican Ostia. Since then, however, a series of new archaeological discoveries in and around Rome has led to a significant revaluation of the oldest Roman history.

Russell Meiggs (1960) was one of the first scholars who again dared to take a stand for the Ostia of Ancus Marcius, although he thought it was an exaggeration to speak of a real 'foundation'. He imagined this Ostia as a small and primitive community, living in huts of straw and clay, which grew its own food and occasionally transported a load of salt to Rome. And since no traces of such a settlement were found under the later castrum, Meiggs suggested a location a little to the east of it, between the Via Ostiensis and the banks of the Tiber, on an elevated site that must have overlooked the salt pans in antiquity. So two Ostias, and that is also what the Roman grammarian Festus says: 'Ostia is at the mouth of the Tiber. According to tradition, it was founded by Ancus Marcius, which concerns either the city or the colony that was founded later'.

The salt road and the Forum Boarium

Only in recent years has it become clear that the history of Ostia probably goes back much further than the regal period. I refer in particular to the work of the Italian scholar Filippo Coarelli, who has placed strong emphasis on the relationship between the salt pans, the Via Salaria (the 'salt road') and the Forum Boarium in Rome (the 'cattle market'), where there was a ford in the river. At least from the Middle and Late Bronze Age (1400-1000 BC), when Rome did not even exist, the salt road was already in use. Nomadic shepherds from the Apennines descended once a year with their herds to the plain of Latium, following the left bank of the Tiber. At the ford, they had their herds cross the river and then continued along the right bank to the coast to collect salt. It is significant that the few Bronze Age shards found in Rome all come from the Forum Boarium (Fig. 1). Such shards may also be found in the lower layers of Ostia. They are well known from similar coastal towns with salt pans, such as Antium, Lavinium and Pyrgi. All this makes it likely that as early as the Bronze Age some huts had already risen at the mouth of the Tiber, seasonally inhabited by shepherds from the mountains.

Fig. 1. Shards from the Bronze Age, originating from the
Forum Boarium in Rome; 14th - 12th century BC.

In the Early Iron Age (1000-750 BC), regular settlements emerged in the plain of Latium, as in Rome. The annual migration of shepherds from the mountains nevertheless remained a familiar event - and it has remained that way until the beginning of our century. The ford in the Tiber, where the shepherds halted with their herds, developed in a natural way into a marketplace for cattle and salt. The emergence of permanent settlements meant that the village that was closest to the salt pans would also exercise some control over these. However, this natural advantage did not accrue to Rome, but to the Latin Ficana on the lower reaches of the Tiber. And it is a virtual certainty that in the Iron Age a permanently inhabited village emerged at the mouth of the river, where residents of Ficana changed the free salt extraction from the past into regulated salt trade. In the early 8th century BC Phoenician seafarers began to show an interest in the rich metal reserves of Etruria. Greek traders followed in their wake and with the establishment of the first Greek colonies in Italy, around 750 BC, a new era began. After centuries of relative isolation, Latium and Etruria now came into close contact with the highly developed cultures of the eastern part of the Mediterranean. The discovery near Ostia of a Sardinian bronze model boat from the 8th century BC is significant against the background of the Phoenician colonization of Sardinia (Fig. 2). Judging by the distribution of imported pottery from this period, the exchange of goods proceeded from that point along the rivers inland.

Fig 2. Bronze model boat from Sardinia, found around 1868 at the mouth
of the Tiber and now in the Hermitage in Leningrad; 8th century BC.

The trade was mainly about metal, with the Etruscan Veii, on the upper reaches of the Tiber, playing a major role. Rome's strategic position in this route immediately proved its value. Archaeological finds from the Forum Boarium indicate that around 750 BC Greek craftsmen and merchants settled here. Roman legends about early contacts with Greek immigrants such as Evander and Greek demigods such as Hercules probably date from the same period. Not surprisingly, these stories usually have the Forum Boarium as a backdrop. It is also noteworthy that in those legends ancient Roman cult practices, but with evident Greek roots, continuously play a role. It indicates that from the very beginning international trade was embedded in a religious atmosphere that united both parties.1

King Ancus Marcius

In the light of this long history it becomes understandable that in the 7th century BC, when the power of Rome grew, the need arose to place the gold vein to the coast under Roman control. If we take a close look at the activities of Ancus Marcius transmitted by tradition, we recognize a well-considered plan to achieve this.

With the help of Lucumo, the competent Etruscan counselor and general who would later succeed him as king Tarquinius Priscus, Ancus Marcius (Fig. 3) carries out the following public and military projects: creating a corridor to the coast through the subjugation of the villages of Politorium and Ficana on the left bank of the Tiber; the conquest of the Maesian forest on the right bank at the expense of Veii; connecting the two banks by means of a wooden bridge, the pons sublicius at the Forum Boarium; strengthening the Janiculus hill on the other side of the river with a fort; 'organizing' the salt extraction at the Tiber estuary, including the pans on the right bank, which had been hijacked from Veii; and finally founding a colony there.

Fig. 3. Bronze coin (as) with a fantasy portrait of king Ancus Marcius and his grandfather
Numa Pompilius. On the reverse, a Victoria statue, two arches (of ship sheds?)
and the ram of a ship refer to Ancus' foundation of Ostia. Early 1st century BC.

The latter took place in 620 BC, towards the end of Ancus' government. It is therefore no exaggeration to say that the foundation of Ostia was the pinnacle of his life's work. But contrary to Meiggs' opinion, the new colony would not have consisted of simple huts. On the contrary, in the time of Ancus Marcius the hut villages in Latium and Etruria abruptly transformed into early-urban communities with houses and temples of stone.2

Ostia in the archaic period

How the town at the mouth of the Tiber further developed in the 6th century BC, can be reconstructed fairly precisely. The government of Tarquinius Priscus heralded a period of unprecedented prosperity for Rome (the so-called Etruscan dynasty). The new colony on the coast will certainly have benefitted from this and expanded considerably. We should not forget that the foundation of Ostia had in fact been the work of Tarquinius Priscus himself, in his capacity as general and counselor of Ancus Marcius.

To give us a more concrete picture of the archaic Ostia, we only have to look at the port towns of Caere and Tarquinia, which have been extensively excavated. Like Rome, both cities founded satellite colonies on the coast towards the end of the 7th century BC, which developed into well-structured emporia in the course of the 6th century. Pyrgi, the emporium of Caere, was centered around two shrines, at least one of which was dedicated to a deity in whom the Etruscans recognized Uni, the Latins Iuno, the Greeks Leukothea and Eileithuia and the Carthaginians Astarte. They were goddesses who did not differ substantially from each other in function and were therefore consciously merged into one internationally recognized deity. Excavations in Gravisca, the emporium of Tarquinia, have uncovered a similar multicultural sanctuary. Here Aphrodite, Hera, Demeter and Adonis were worshipped, deities that must have appealed to every Greek or Carthaginian. At the sanctuary of Pyrgi, temple prostitution was even conducted, a familiar practice for Punic and Greek seafarers, that was effortlessly taken over by the Italic trading partners (Fig. 4). A long inscription, written on gold leaf, was attached to the door of one of the Pyrgi temples, in which the king of Caere proclaimed the foundation of the sanctuary bilingually, in Etruscan and Punic. In short, the impression that the excavations in these port cities give us is that of thriving centers of international traffic, within which temples more or less played the role of commercial embassies.

Fig. 4. The temple complex in Pyrgi, the emporium of Caere; 6th century BC.
It is believed that the small rooms on the east side were used by the temple prostitutes.

An emporium in Rome

That 6th-century Ostia formed a similar emporium is, for the time being, no more than an assumption. What we know for sure is that the mighty Rome of the archaic period was not inferior to Caere and Tarquinia in the area of international relations either. The historian Justinus (43. 3.4) tells how at the time of the Etruscan dynasty a group of young people from Phocaea (Asia Minor) sailed up the Tiber to make friends with the Romans. Such an event fits in perfectly with the image we have of the archaic emporia, especially since such an agreement will have been concluded under the watchful eye of a deity recognized by both parties.

Justinus' note also sheds light on the question why Rome in particular occupied such a considerable position in Central Italy. It had an advantage because of its unique location on the Tiber, which was navigable from Ostia to the Tiber Island for (rowed) sea-going vessels. The river thus formed a direct axis between the coast and the city, with Ostia at one end and the Forum Boarium at the other. And while the emporium of Ostia is still awaiting discovery, the 'branch' in Rome is known archaeologically.

Excavations at the church of S. Omobono, in the heart of the Forum Boarium, have shown that this area underwent a total transformation between the late 7th century and entire 6th century BC. The old cattle market and trading place was converted into a monumental and ultra-modern emporium, which was provided with all comforts, including multicultural shrines and temple prostitutes. This shows once again how closely the history of the Forum Boarium is interwoven with that of Ostia.

Between regal period and castrum

The emporium of Ostia must have been in full operation when the Etruscan monarchy was overturned in 509 BC. We can deduce this from the treaty that Rome, according to the historian Polybius (3.22), concluded with Carthage in the same year. It was probably a smart diplomatic move by the new rulers to renew an agreement in their own name that had previously been concluded with Carthage by the expelled king Tarquinius Superbus or his predecessor(s). That such agreements already existed in the archaic period is evident from the aforementioned inscription of Pyrgi.

Shortly after 500 BC however, Rome soon loses control of the vast territory it had taken over as inheritance from Tarquinius Superbus. The Latins revolt and southern Latium is lost to the Volsci. The important port city of Antium, 50 kilometers below Rome, becomes a stronghold of piracy. Internally, Rome is struggling with serious social unrest and repeated famine. The overall decline to which the city is subject in the 5th century is reflected, among other things, in a drastic fall in international contacts. This will also have effected Ostia. The right bank of the Tiber is again lost to Veii and the Forum Boarium is undergoing a phase of deep decline. In Livius' account of the 5th century BC Ostia is only mentioned twice (14. 13-16 and 14. 30. 5-6), casually and in situations that make it clear that there was no longer an international emporium.3

Fig. 5. The republican castrum of Ostia (reconstruction); early 3rd century BC.

Republican Ostia

Until recently there was agreement that the castrum, the rectangular fortress on the site of the later forum of Ostia, was founded in the 4th century BC (Fig. 5). This despite the fact that Livius, whose historical work has been completely handed down for this period, makes no mention at all of the event. In the absence of better information, scholars have done their best to place the foundation of the castrum in a plausible historical context with the help of 'surrounding' data.

A reliable terminus post quem is the definitive conquest of Veii in the year 396 BC. After all, the new colony with a fort can only have fulfilled a meaningful function from the moment that Rome (again) possessed the entire mouth of the Tiber. An absolutely certain terminus ante quem is the year 267 BC, when Rome established a new magistrature for the fleet and assigned a permanent seat to one of the officials permanently in Ostia (Lydus, De magistratibus 1. 27). Three years later, the First Punic War broke out and Rome would make history for the first time as a seafaring force.

Within these broad limits we find a first starting point for a possible foundation date of the castrum in the years 349/348 BC. Livius (7. 25. 4) says that Greek ships then raided the coast of Latium between Antium and the Tiber estuary; subsequently the sea contract between Rome and Carthage was renewed (Livius 6. 27. 2 and Diodorus Siculus 14. 69. 1). It seems plausible that at that time the derelict harbour town was also revived to put a stop to the looters. The second point of reference is the year 338 BC, when Rome, after a fierce century and a half of war with Latins and Volsci, finally regained hegemony over Latium. It was on that occasion that the fleet of the hostile Antium was dismantled. The rams of the captured ships were shown triumphantly on the Forum Romanum and attached forever to the speakers' podium, which was since then called Rostra ('the rams'). With the fall of Antium, Rome was once again in full control of the entire coastline of Latium. This almost hás to mean that the military colony in Ostia was now operational. The oldest pottery finds from the castrum fit in well with this historical reconstruction: they provide datings between 380 and 340 BC.4

New dates, new discussion

At least, this is what was thought until 1988, when the always opinionated Filippo Coarelli put the cat among the pigeons. According to him, the castrum had been founded already in the late 5th century BC, so before the conquest of Veii. He based himself mainly on the fact that the fort has been built with a kind of tuff that only occurs near the city of Fidenae. He attributes great importance to this, because after the conquest of Veii in 396 BC especially the quarries of this city were exploited (the so-called Grotta Oscura-tuff, which has a clearly different structure). Since Livius places the conquest of Fidenae in 435 BC (4. 22. 2), the conclusion is clear to Coarelli: the construction of the fort must have started shortly afterwards and have been completed before the fall of Veii.

The discussion has not become any easier now that Archer Martin recently (1996) has launched a date that is much lower than the generally accepted date. Indeed, probes along the foundation walls of the castrum appear to yield only finds from the period between 300 and 275 BC. And so the founding date of the castrum shifts to the early 3rd century BC!

Two such contrasting views require comment. Regarding the 'high' date: it is useful for the reader to know that the proposing of revolutionary dates for antique buildings based on the type of stone used is one of Coarelli's pet subjects. But many archaeologists are rightly quite skeptical about this method, because we know little or nothing about the considerations that played a role in the mining of quarries. The 'low' date, however, should in my opinion be taken seriously. Because while all previous datings are derived in a forced manner from historical data and are therefore strongly hypothetical in nature, this dating is so far the only one based on hard archaeological evidence.5

Fig. 6. Shards from the castrum. Two fragments of a red-figured Attic drinking bowl, 375-350 BC.

4th century or 3rd century?

The first question that then arises is how a date between 300 and 275 BC can be reconciled with the aforementioned shards of 4th-century pottery that were also dug up in the castrum. Well, these shards are all from painted mixing vessels and drinking bowls. Such luxury pottery certainly did not belong to the standard kitchen equipment of an army site. However, it was often left as a votive gift in temples. And indeed there are indications that there was a sanctuary on the site of the later castrum that goes back at least to the early 5th century BC, and probably even to the time of the archaic emporium. It is therefore quite possible that the 4th-century shards actually have nothing to do with the castrum, but with an older phase of Ostia.

A second question that arises is what is wrong with the arguments from ancient history that seem to argue for a foundation shortly after 350 BC. Here, too, the story appears not to be as solid as one would think at first glance. The fact that the Roman-Carthaginian sea treaty was renewed in 348 BC does not mean that the delapidated harbour construction in Ostia was immediately rebuilt and reinforced with a fort. After all, since the archaic period Rome also had a harbour in the city, the Navalia near the Tiber Island. Without a doubt, in the course of the 5th century BC, when it was no longer able to exercise effective control over the coastal strip, Rome brought its ships together within the city harbour. That the Navalia remained in use until far into the 4th century as thé naval facility of Rome is evident from events after the conquest of Antium. The captured fleet, according to Livius (8. 14. 12), 'was partly transferred to the Navalia in Rome, partly burned'. The remarkable fact that Ostia is not mentioned is directly related to the equally remarkable fact that part of the fleet was destroyed. It betrays that Rome had little use for these precious spoils of war, no more in any case than the limited capacity of the Navalia allowed. And if in these years Rome felt the need to create a more direct access to the sea, which is very likely, then the conquest of Antium would have amply met that need: the port of Antium (Anzio) is regarded until the present day day as the best in Latium.

Thus it appears that the events between 349 and 338 BC, properly considered, do not contain any indication of the existence of a fortified harbour in Ostia, as has always been assumed. The opposite is true: the foundation of the republican Ostia must have occurred áfter 338 BC. The year 267 BC mentioned earlier is still a safe 'lower limit', when a special magistrature was installed for the fleet in Ostia. These are therefore the two margins within which a plausible foundation date for the castrum can be sought.

The arrival of Aesculapius in Rome

Since Archer Martin postulated his 'low date', only the Italian Fausto Zevi has made a suggestion for a new historical context. His thoughts go to the year 312 BC, when Rome first appointed two 'ship officials', the duumviri navales (Livius 9. 30. 4). Certainly this is an indication that Rome was now re-orientating itself at sea. But unfortunately Livius does not tell where these shipping officials held a seat. We must therefore allow for the possibility that their activities were aimed at ships that were stationed in the Navalia or in the port of Antium.

That this is not imaginary is evident from the tradition concerning the god Aesculapius, who in 292/291 BC was brought from Epidaurus to Rome in the form of a snake. In his book with historical anecdotes, Valerius Maximus (1. 8. 2) tells how the ship carrying the deity entered the port of Antium. Here the snake escaped to hide for three days in a neighboring sanctuary, nestled high in a tree. When the snake had finally been lured back on board, the boat sailed swiftly to the Tiber mouth and upstream to the Navalia. There the snake slipped off board again and swam to the Tiber Island, where its new sanctuary was then built. Not only the role of the Navalia in this story, but also that of Antium makes one think. Why would a ship with such an important cargo on board moor in Antium if the home port was already in sight? The continuation of the narration too, in which the ship sails on directly to the Navalia without a mention of Ostia, leaves only one conclusion open: in 292/291 BC the republican castrum had not yet been built and the seaport of Antium, together with the city harbour, functioned as the only ship facility of Rome.

The port of Antium, however, turned out not to be very suitable as a 'face to the sea' for international relations. The geographer Strabo (5.5 3.5) tells how first Alexander, king of Epirus, and later Demetrius Poliorcetes complained to Rome about continuing piracy from Antium. Because Rome controlled this city, it was also held responsible for the misconduct of the Antiates. The first episode, with Alexander of Epirus, takes place between 332 and 326 BC, the second around 300 BC ('thirty years later', says Strabo). Such incidents may have led Rome to decide to build its own military port at the mouth of the Tiber after all, under direct management of and guarded by a permanent garrison. But the way in which Aesculapius made his entrance into Rome indicates that such plans had not yet been realized in 293/292 BC. Fifteen years later they had. Justinus (18. 3. 4) reports that in 278 BC, during the war with Pyrrhus, Carthage sent a fleet of 120 ships to help Rome. This fleet landed in Ostia, not in Antium. This is the first clear indication of the existence of port strength at Ostia.

The coming of Aesculapius to Rome is also relevant in another respect for the discussion about the founding date of Ostia. The earlier history of this story is that Rome in 293 BC was plagued by a devastating epidemic. Because the indigenous gods were unable to reverse the disaster, it was decided to send an embassy to the healing god of Epidaurus. However, the consuls were engaged in war, so that the mission was postponed for a year. This is what Livius writes in the last lines of his tenth book. The subsequent book XI, in which the journey of the mission was undoubtedly described, and the books XII-XX, have unfortunately been lost. This explains why the founding date of republican Ostia is not known to us from historical sources.








Fragments of an inscription mentioning king Ancus Marcius.
From the Imperial period, found in Ostia.


Ostia can rely on a long history that is inextricably linked to the extraction of salt at the Tiber estuary and the parallel development of the Forum Boarium in Rome. The traditional foundation of Ostia by king Ancus Marcius, in the late 7th century BC, is more likely to have meant the structuring of an existing settlement than a new one. From that moment on, Ostia was converted into an advanced trading post of Rome, aimed on the one hand at controlling the salt trade and on the other at large-scale trade with Greeks and Carthaginians. The emporium experienced a heyday in the 6th century BC, but rapidly declined after the end of the regal period. Subsequently, the coastal town led a sleepy life, until the colony was re-founded and fortified with a fortress.

It seems that the 4th century shards from the castrum have led the scientists astray when it comes to the foundation of the republican Ostia. Probably it concerns (fragments of) votive gifts from an older sanctuary in the same place. The latest excavation data indicate that the castrum must have been built between 300 and 275 BC. Historical data suggest a further framework between 292/291 BC, when the god Aesculapius was brought to Rome but apparently the castrum did not yet exist, and the arrival of a Carthaginian fleet at Ostia in 278 BC. The re-founding was probably described in Book XI of Livius, which has not been handed down.


1. The relationship between the Via Salaria, the Forum Boarium in Rome and the earliest Ostia has been discussed extensively by F. Coarelli, Il Foro Boario. Dalle origini alla fine della Repubblica (Roma 1988).
2. The most extensive tradition about the foundation of Ostia by king Ancus Marcius can be found in Livius, Annals I. 3 and in Dionysius of Halicarnassus, Roman Antiquities 3. 44.
3. For a reconstruction of the turbulent times that Rome and Latium went through after the fall of the monarchy in 509 BC, see D.J. Waarsenburg, Satricum, the Temples and the Lapis, Lampas 29/1 (1996) 27-45.
4. All literature on the founding date of the republican castrum is collected in F. Zevi, Sulle fasi più antiche di Ostia, in Gallina Zevi-Claridge (ed., 1996) 69-89.
5. Coarelli gives a 5th-century dating of the castrum in his contribution I santuari, il fiume, gli empori, Storia di Roma I (Torino 1988) 127-151. For the 3rd century dating see A. Martin, Un saggio sulle mura del castrum di Ostia (Reg. I, x 3), in Gallina Zevi-Claridge (1996) 19-38. The story of Aesculapius' journey to Italy is also told by the Auctor de viris illustribus, in Aesculapii Romam advectio; and by Ovid in his Metamorphoses 15. 622-744.

Translated from the Dutch by Jan Theo Bakker.

[jthb - 8-Mar-2020]