To the north of the entrance channel leading to Trajan's hexagon and to the west of the Imperial Palace is a very large warehouse known as the Great Horrea of Septimius Severus. The name was given by Giuseppe Lugli in 1935 because of the date proposed by him, based on red bricks that are characteristic for the Severan period. However, Herbert Bloch found four brick stamps that indicate a date in the first ten years of the reign of Marcus Aurelius (unless they are reused material or belong to repairs).
The area with the Great Horrea of Septimius Severus (D). Map: Portus Project.
Plan of the horrea. Testaguzza 1970, p. 192, based on Italo Gismondi's plan.On Luigi Canina's plan from 1827 only a few walls can be seen, but in 1835 quite a few rooms must have been excavated, witness the plan from that year by Pierre-Joseph Garrez. Guido Calza's description of Portus from 1925 makes it clear that the building was largely buried (again?). The first really accurate plan was made by Italo Gismondi in 1933 and published by Giuseppe Lugli in 1935.
The east side of the horrea, seen from the south. Photo: Parco Archeologico di Ostia.
The east side of the horrea, seen from the north, with Trajan's basin in the background. Photo: Portus Project.
The north side of the horrea, seen from the east. Photo: Jan Theo Bakker.
The north side of the horrea, seen from the west. Photo: Jan Theo Bakker.Geoffrey Rickman, writing in 1971, explains: "It consisted of three ranges of rooms of unequal length, grouped around an open cortile. The north range was about 186 metres long, the east range 108 metres and the west some 65 metres long. The south side of the courtyard was open on to the sea-way between the two harbours. A corridor 5.40 metres wide surrounded the cortile on the three sides in front of the ranges of rooms which opened on to it. This corridor was covered with cross-vaulting and was lighted by doors and windows into the courtyard. Although the rooms only opened on to the corridor and courtyard which faced towards the Darsena, there was an entranceway in the middle of the north side which led to the wharfs around the Claudian harbour. The rooms varied in size, those on the east side being the deepest, 17 x 5 metres. All the rooms had wide arched entrances."
The passage in the centre of the north side, seen from the south. Photo: Jan Theo Bakker.Rickman continues: "A travertine threshold was recorded in 1925, 2.35 x 0.60 metres, with two pivot holes 2.05 metres apart. This is exactly similar to the thresholds of horrea in Ostia itself. On the east side the rooms have two pilasters on each side wall from which spring the four ribs dividing the cross-vaulting at a height of 3.10 metres from the floor. On the north and west sides the rooms have only one such pilaster on each side wall. In the rear wall of each room were two tall splayed windows, presenting to the exterior narrow slits between the buttresses along the sides. These buttresses were arranged at regular intervals half the width of each room so that they corresponded either to the division walls of the rooms or to their axis. The windows on the north side were blocked at a later date by the building of new walls inside and outside the original wall. Calza in 1925 revealed that the flooring was of 'cocciopesto' (opus signinum) 10 centimetres thick."
The interior of a cella. Photo: Jan Theo Bakker.
A room in the south-east part. Photo: Jan Theo Bakker.Rickman again: "Two ramp stairways in the east range and two in the north range led to an upper storey. The fact that the staircases are in the form of ramps makes it clear that as in the Piccolo Mercato in Ostia we have upper storeys devoted to storage purposes. The whole building was finely constructed and faced with brickwork, the caementa consisting of fragments of tufa together with pieces of sherd, selce and marble. A reconstruction drawing of this building is given in Lugli's book (fig. 51) and can be regarded as a fairly accurate impression of its appearance. It would be right to doubt the artist's assumption that the external buttresses were joined at the top by arches thus making rather graceful blind arcades, in view of the rarity of positive evidence for this type of structure. It is perhaps more likely that the buttresses were taken straight up to the roof."
Reconstruction drawing of the exterior of the horrea, seen from the south-east, from the hexagon.
Lugli-Filibeck 1935, fig. 51.
Reconstruction drawing of the horrea, seen from the south-west, by Italo Gismondi.
Museo della Civiltà Romana. Testaguzza 1970, p. 192.In the door-jambs of the cellae are travertine corner-stones, with holes in the front. Their function is not clear. The cellae did not have raised floors, used in grain warehouses, so perhaps olive oil or wine was stored here.
Detail of the entrance of a cella, with travertine corner-stones. Photo: Jan Theo Bakker.In the fourth century a wall of opus vittatum was built against the outer north wall of the Great Horrea of Septimius Severus. In front of this wall is a porticus.
Between the warehouse and the Baths of the Small Lighthouse, so to the west, geophyiscal research performed by the Portus Project revealed an open space or courtyard (c. 60 x 40 m.) surrounded by ranges of rooms. In the northwest corner is a distinct rectangular structure (c. 12 x 15 m.) with additional room divisions. The function of this building remains unknown.
Computer reconstruction of the horrea. Image: Portus Project.Sources
Calza 1925, 68; Lugli-Filibeck 1935, 83-86; Bloch 1938, 279-280; Rickman 1971, 128-130; Keay et al. 2005, passim.
