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Regio I - Insula XII - Terme del Foro (I,XII,6)

To the south-east of the Forum is one of the largest baths in Ostia, the Baths of the Forum. The total area is c. 3200 square meters. Several phases can be distinguished, on the basis of inscriptions and brick stamps (all masonry is opus latericium, with the exception of the last phase, which also has some opus vittatum):

The building was plundered in the early 19th century and probably at other moments. The final excavation took place during a long period, in the years 1920-1941. Some minor work was carried out in 1959 and 1980.

Originally the walls had marble revetment to a height of approximately three meters, with plaster above. The floors were decorated with black-and-white mosaics with geometrical motifs (in the sweating room the ibis is depicted). At the end of the fourth century the walls and floors of many rooms were decorated with marble - often re-used material. Many statues were found in the baths, but it is often uncertain whether they belong to the building. This is almost certain however for two statues of deities of health (Hygieia and Aesculapius), for a statue of Fortuna (from the same workshop as the statue of Hygieia), and for the head of a pugilist from the palaestra (referring to the physical exercise that took place there).

The cold rooms are in the northern, rectangular part of the building. They had cross-vaults. To the south are the warm rooms. Room 16 had an ellipsoidal vault, rooms 17 to 19 probably barrel-vaults. The south facade is much varied. It was designed in such a way that the rooms received a maximum of sunlight in the afternoon, from the west, through huge windows. The windows must have had glass in wooden frames, in order to maintain the correct temperature. Only room 15 (used for sun-bathing) may have had open windows.

Plan of the baths

Plan of the baths. After SO I.

The building was entered originally through vestibules 2 and 14. At the end of the fourth century room 1 took over this function from room 2. Room 1 was accessible from the Forum and the palaestra. The main entrance to room 2, from Via della Forica, was now blocked, as were two windows, on either side of this entrance, and a secondary entrance from the palaestra (most of this masonry was removed by the excavators). There were changes to the ceiling, which may explain the addition of two pairs of arches spanning Via della Forica, supporting the facade. The northern part of room 2 was originally separated from the rest of the room through marble columns. Between the columns and the north wall two walls were now built, possibly creating extra changing-rooms.

Visitors proceeded to the changing-rooms (apodyteria) 4, 5, 12 and 13. In the entrance of each room were two marble columns. Rooms 4 and 12 had three windows in the north wall. Between the changing-rooms is the cold bath (frigidarium), 6. It was surrounded by large marble columns. The height of the room must have been 15-17 meters. To the north and south are basins, that may have had columns on the partition-walls. They had niches in the back- and side-walls. The niches in the north basin were blocked when an apse was added in the early fourth century. Holes and imprints of lead pipes show that there was a jet of water below each niche. Rooms 7 and 8 had a large window in the north wall.

The octagonal room 15 was used for sun-bathing (heliocaminus). It had relatively few artificial heating, and the largest windows. Room 16 was a sweating room (sudatorium). Along the walls are marble seats. The room seems to have been closed off with double doors. Rooms 17 and 18 were lukewarm (tepidaria). There are no basins here, because tepidaria were only transitional rooms, where people could rest and relax. Holes in the square columns of room 18 were used to fasten window-frames. Room 19 was a hot bath (caldarium), with three basins. In these basins many hairpins were found, proving that women also used the baths. In the early fourth century an apse was added to the southern basin. The apse has round columns; vertical bands of mortar on the columns are all that remains of the windows.

To the east of the caldarium are the ovens (praefurnia), which heated the air that passed through the hollow floors (hypocausts). The heating system was improved in the Severan period and in the early fourth century. Along the east side of the ovens runs a corridor. To the north-east of that is a secondary entrance, outside of which are two huge arches with two storeys. They contain some very late masonry, but may have been built in the Severan period. It has been suggested that they were connected to the aqueduct. However, the second storey is 13.9 metres above sea-level, whereas the Ostian aqueduct was at a height of 8 metres. To the south-east of the corridor was a waterwheel with a diameter of c. 10 meters. With this wheel slaves lifted ground water, which was collected in a huge cistern to the north.

To the south of the warm rooms is the palaestra. The surrounding rooms were built in the late-Antonine and early-Severan period. To the latter period belong the brick piers of the porticus. In the early fourth century many different kinds of marble and granite columns were added. The variety seems to have been a conscious choice. In the south-west part of the palaestra are one or two small temples. Two objects may belong to them. First of all a terracotta antefix from the first or second century AD. It was found in the smaller of the two structures. We see a well-known motif: a winged Victoria killing a bull. A row of antefixes will have decorated the upper part of the shrine. Secondly a votive group, with the depiction of a snake, Aesculapius, and two goddesses on a couch (perhaps Ceres and Proserpina). This object was found in the rooms to the south of the palaestra. It may be related to a lectisternium, a meal at which the gods were thought to be present, lying on a lectus. The reference to new life (Ceres / Proserpina), and the relation that was made by the Romans between baths and health suggests that it was held during an epidemic. To the southwest of the shrines is a large latrine, with more than twenty seats.

The rooms to the south and west of the palaestra have been numbered separately (I,XII,8, 9, and 10).

M. Gavius Maximus

The construction started at the end of the reign of Antoninus Pius, c. 160 AD. It was financed by M. Gavius Maximus, who for a period of twenty years was praefectus praetorio (138/139 - 158/159 AD). A lead waterpipe was found in the palaestra with the stamp M. Gavi Maximi pr(aefecti) pr(aetorio) e(minentissimi). In or near the baths part of an honorary inscription was found: M. Gavi[o --] | Maxim[o--] | P[raef. pra]et[--]. The baths were even named after him: Thermae Gavi Maximi. This name is found on fragments of an architrave:


After SO XI, Tav. X (the distance between the fragments is uncertain).

Vetustatis incuria [---] conf[i]rm[atis--- ther]mis Gavi Ma[ximi ---]ito[---] |
Dominorum nostro[rum --] aete[r]no[rum principum --- loca proxi]ma fori et ian[uae --- Ho?]nor[i-? ---]

The inscription has been dated to late antiquity on the basis of the writing. At the end of the second line we may see part of the name of the Emperor Honorius (393-423 AD). We read that the building (near the Forum and an arch) was in disrepair.

M. Gavius Maximus was born c. 80 AD and died in 158 or 159. The building was finished after his death, during the reign of Marcus Aurelius (161-180 AD). It is not clear why Maximus financed the building: the praefectus praetorio in Rome had no specific relation with Ostia. Perhaps a clue is offered by Hadrianic baths that had been built to the north. All that can now be seen of these baths are the remains of a large hall in the Caseggiato della Cisterna (I,XII,4), in which a bakers' oven was installed. The destruction of these baths is usually dated to late antiquity. It is conceivable however, that the Baths of the Forum replaced the Hadrianic baths (destroyed by fire?). Maximus may have financed the Hadrianic baths when he did have a tie with Ostia, for example as prefect of a fleet (praefectus classium praetoriarum Misenensis et Ravennatis). He may have rebuilt his own baths.

Fl. Octavius Victor

The work of Fl. Octavius Victor is documented by a few inscriptions. In the frigidarium are fragments of an architrave belonging to the northern basin (another fragment is in Rome). They carry Greek inscriptions:

... a hexameter and a pentameter. The baths were restored by Victor, "an eminent man in Italy because of his important duties". He is presumably the praefectus annonae, whose name is also read on another fragment from the baths, with the text [-- cura]nte Fl(avio) Octavio V[ictore --].

We hear of "healing baths", or "baths that drive away sorrow" (loutron alexiponon). Meiggs has drawn our attention to a few sentences in Augustine's Confessions (9,12,32). After the death of his mother Monica, in Ostia, Augustine visited baths, "because I had heard baths were called balnea from the greek balaneion, which means driving away care from the mind". Had Augustine seen the Greek inscription in the Baths of Forum?

Part of an architrave in the Vatican has the same measurements and decoration as the fragments with Greek inscriptions. This architrave has a Latin inscription, the beginning of two hexameters:


From SO XI, Tav. XIII

Maximus has olim therm[as --] |
Divinae mentis ductu cum o[--]
(the last letter is an o, c, or g).

Again we read the name of M. Gavius Maximus. According to Meiggs the text may be Constantinian, because it recalls a phrase on the Arch of Constantine in Rome: instinctu divinitatis.

Ragonius Vincentius Celsus

It is not certain that Ragonius Vincentius Celsus was involved with restoration of the baths, but it seems likely. In room 1 is an architrave, that was found partly in the baths, and partly in the nearby Exedra I,XII,3. It was at least 4.68 meters long, and seems to have been carried by four slender columns. It has an inscription that is identical to the inscriptions on two bases, one of which was found on the Forum:

Curavit Ragonius Vincentius Celsus, v(ir) c(larissimus), praefectus annonae urbis Romae, et civitas fecit memorata de proprio

... "Ragonius Vincentius Celsus, a most illustrious man, prefect of the grain supply of Rome [did what?], and the grateful citizens [did what?] on their own expense". To which monument does the architrave, that is relatively small, belong? Various suggestions have been made. The most recent research suggests that it formed part of some sort of vestibule without a roof to the west of room 1. Possibly the prefect had financed restorations in the baths, and Ostia the commemorative structure near room 1. A statue of either Ragonius Vincentius Celsus or Q. Aurelius Symmachus (another dignitary) was found in the west part of the palaestra.


Photographs and drawings



View across the palaestra towards the southern rooms. From the south-west.
Photograph: Jan Theo Bakker.



View towards the frigidarium, from the west. Photograph: Jan Theo Bakker.


Detail of a capital in the frigdarium.
Photograph: Jan Theo Bakker.



The columns of room 18, with two rows of holes for fastening window-frames.
In some of the holes metal has been preserved. Seen from the south-west.
Photograph: Jan Theo Bakker.



Vertical bands of mortar on a column of room 19,
for fastening a window-frame. Photograph: Jan Theo Bakker.



Arches to the east of the baths, perhaps connected to the aqueduct.
From the south-east. Photograph: Simon Bakker.



Fragment of an architrave with Greek inscription. Photograph: Jan Theo Bakker.


Fragment of an architrave with Greek inscription. Photograph: Jan Theo Bakker.


Fragment of an architrave with Latin inscription mentioning Ragonius Vincentius Celsus.
Photograph: Jan Theo Bakker.



Basis with Latin inscription mentioning Ragonius Vincentius Celsus.
Photograph: Jan Theo Bakker.



The southernmost shrine in the south part of the palestra, seen from the east.
Photograph: Jan Theo Bakker.



The latrine to the south-west of the shrines. Photograph: Jan Theo Bakker.


The latrine to the south-west of the shrines, detail.
Photograph: Eric Taylor.



Transverse section of rooms 6 and 17, from the west. From Johnson 1932, Plate 45.


Photograph taken during the excavation of room 2.
From the south. The blocking of the northern entrance
of the room was later removed by the excavators.
From SO XI, Fig. 16.

[jthb - 13-May-2006]