THE RAISING OF OSTIA AND TIBER INUNDATIONS
An unexpected phenomenon is the raising of Ostia in late antiquity. From an unknown point in time, building rubble, rubbish and sherds were dumped on the streets, on top of the basalt blocks. Sometimes several layers were found, on top of each other. The excavators speak of "terra battuta" on top of each layer, "rammed earth", so it seems that the raised streets were still being used as such, although of course there was no question anymore of normal transport and proper water-supply and -drainage.
In the north-west part of town the phenomenon is documented in front of the Warehouse of Epagathus and Epaphroditus (I,VIII,3). Here the height of the layer was only 0.70 metres. Collapsed walls were found on top. Around the House of Cupid and Psyche (I,IV,5) the layers had a height of 1 to 2 meters. The layers were also found to the north-east of the Forum. In front of the House of the Millstones, on Via dei Molini, the height varies from 2.20 to more than 3 meters. Here the layers are on top of collapsed walls. On Via dei Balconi and Via di Diana the layers were 2 to 5 meters high. They consisted mainly of many sherds of amphorae that had been dumped on top of the basalt blocks of the street, covering the width of the street. Dumped sherds were however also found on top of collapsed masonry. The layers were furthermore found inside the Block of the Paintings (I,IV), both in the interior of the buildings and in the garden around which they are arranged. The layers were found in front of the theatre, partly resulting from a fire, 1.5 meters high, with collapsed walls on top. On the north part of Via delle Corporazioni the height was 1.45, on the south part 0.35, here with collapsed walls of the theatre on top.
The raising was not restricted to the north part of town. Layers similar to those near the Tiber were found on Via del Sabazeo, in the south-east part of the city. On a street near the Christian Basilica on the Pianabella, much further to the south, a succession of layers was found reaching a height of 0.80 to 1 meter, created from c. 350 AD to the early seventh century. On top collapsed tombs were found. A filling of sherds and bricks was found in the Shrine of the Three Naves (III,II,12), a shrine to the east of the House of the Charioteers (III,X,1), in the central part of the city. In the House of the Painted Vaults (III,V,1) a ceiling with beautiful paintings was found intact. The room could be entered by the excavators through a window, after which they climbed on a filling, the composition of which unfortunately is not described.
All in all hundreds of meters of street, sometimes seven meters wide, were raised in this way. The precise extent is unknown, because of a lack of detail in the excavation reports. On and around Via dei Balconi Guido Calza noted an almost complete absence of bricks in the layers, that is of the building material of the upper floors. He suggests that upper floors were torn down in late antiquity, for the collection of bricks. We now know that often there was no need to tear down the walls: earthquakes had made them collapse. The bricks would have been reused in the south part of Ostia, where wealthy dwellings (domus) were installed, and in Portus. During the 1938-1942 excavations it was noted that basalt blocks of streets had been removed. As we shall see later on, building material was extracted as late as the 16th century.
We know little about the chronology of these layers. In some layers many amphorae from the middle of the fourth century were identified. In others coins were found of Claudius II Gothicus (268-270) and Maxentius (306-312). It is hard to believe that the raising continued substantially after the first quarter of the fifth century, when the last significant building activity took place in Ostia.
In the Block of the Paintings, in the House of Diana, and on the surrounding roads the layers on the street were eventually as high as the ground floor, and in late antiquity or the early mediaeval period some people lived on top: the first upper floor had for them become the ground floor. Flimsy walls of opus vittatum (brick and tufa) belonging to this phase were found by the excavators, who removed them (Guido Calza remarked: "sarebbe meglio non ci fosse", "it would better not be there"). Similar late-antique or early-mediaeval walls were removed throughout Ostia, which was often not documented. In the House of the Priestesses windows and doors above the destruction layer of the late third century were blocked, probably in the fourth or fifth century, suggesting habitation. But no substantial architecture, no wall paintings, no statues, no inscriptions testify to these late inhabitants.
Where did all the material come from and why was it dumped inside the city, instead of the swamp to the east of the city, where much of the rubble resulting from the fire in Rome in 64 AD had been dumped? The raising along the Tiber was presumably a protection against Tiber floodings. The layers are however also encountered in the south part of the city, far from the Tiber. It looks as if the high level was not just intended as a dyke, but as a new ground floor- and street-level, created because the entire city was periodically flooded. Presumably the rubble resulted, at least partly, from the various earthquakes. On the other hand the presence of sherds of amphorae points to commercial activity. Partly we may witness the use of an Ostian "Monte Testaccio" as a quarry.
Eventually the wooden beams supporting the ceilings rotted away, leading to the collapse of the buildings. And of course the buildings were plundered, before and after the collapse. Various pagan structures seem to have been destroyed by Christians, after the conversion of Constantine. To the south of the House of Diana is a little square (Square of the Lares) with a crossroads-shrine, a compitum. To the shrine belongs a round, marble altar. Parts of the upper cornice and the inscription have been hammered off, and the reliefs were heavily damaged. Some of the fragments were found nearby, one had been used for the repair of a road. The statue of Mithras in the Mithraeum of the Baths of Mithras (I,VII,2) was seriously damaged, and parts were thrown in a drain. It is probably not a coincidence that a Christian oratory or little church was built on top of the mithraeum, in the second half of the fourth or in the fifth century.
The worshippers of the Magna Mater seem to have been prepared for disaster, expected destruction by Christians, or perhaps rather by approaching Goths or Vandals. Many dedications by the guild of the reed-bearers (cannophori) were found in the central niche in the back wall of the podium of the Temple of the Magna Mater (IV,I,1), walled in. Several objects from the nearby Sanctuary of Attis (IV,I,3) seem to have been hidden in the porticus along the south side of the Field of the Magna Mater.
Flooding of the centre of Ostia in 1938.
Photo: Archivio Fotografico Ostia, neg. B 2588.
A late antique or early mediaeval door on the first floor of the
House of the Paintings (I,IV,4), created when the ground floor was buried.
From DeLaine 1995, fig. 5.9.
A late-antique or early mediaeval blocking in the porticus of the Baths of Neptune.
Photo: Archivio Fotografico Ostia, neg. B 1918.
Ongoing excavations in the House of Hercules in 1940 and the current situation.
Photo left: Archivio Fotografico Ostia, neg. B 2912.
The podium of the Temple of the Magna Mater.
Statues had been walled in in the central niche of the back side (left).