The House of the Millstones in Ostia Antiqua, June 1995

Regio I - Insula III - Caseggiato dei Molini (I,III,1)

The excavation of the House of the Millstones was completed in the years 1913-1916, by Raffaele Finelli and Guido Calza. The building had been excavated partially in 1870 by Carlo Ludovico and Pietro Ercole Visconti. Because of political events the Visconti's could not finish the excavation. Ostia was property of the pope, but on September 20th 1870 king Victor Emanuel captured Rome. The pope retreated to the Vatican, and Ostia was from now on under the authority of the new Italian state. After the first excavations the building was named Casa di Aquilina, after a stamp on a lead water-pipe, found below the pavement of Via dei Molini. When the excavations were continued in 1913, most of the rooms that had previously been excavated had been filled with earth again. Objects found in the building were stolen twice: in 1870 and 1959.

Phase 1: the Hadrianic period

The building was erected in the early second century AD, during the reign of Hadrian (opus mixtum). It consisted of shops along Via dei Molini, a hall at the intersection of Via dei Molini and Via di Diana (1-3), and two halls (17-18, 19-21) and a few rooms behind the shops. In the east facade two recesses for reliefs have been preserved. One is now empty, in the other is a terracotta relief of a Genius with cornucopiae and patera, and a snake. The snake represents the Genius Loci, the protective deity of the place.

Phase 2: the Antonine period

In the Antonine period the House of Diana was built to the west. There was an alley between the two buildings. In the same period the House of the Millstones was modified (opus latericium). Shops 15 and 16 were built or perhaps rebuilt. Slender brick piers were set against the west and east wall in halls 17-18 and 19-21. They do not seem to have supported a roof. Room 17 seems to have been the only part of the halls that was covered, witness beamholes. Room 8 apparently had a special status. It was not accessible from the street, but received light from it through two windows. Two more recesses for (lost) reliefs were added, in the east and south facade. There are two external staircases: room 4 (already a staircase in the Hadrianic period) and room 9. The steps rested on wooden beams, fastened in small holes in the lateral walls. The first floor in the east part of the building was at a height of a little over four metres. Via di Diana was partly blocked by a short wall set against the east end of the facade. There is a pendant across the street.

Phase 3: the Severan period

Important structural modifications took place in the Severan period (opus latericium). Five sub-phases have been recognized. The modifications began during the reign of Septimius Severus (193-211 AD). The work was finished during the first decades of the third century. The main alteration was the raising of the level of the upper floors. A new first floor was installed at a height of c. 6 metres. The other upper floors must also have been rebuilt. This destabilized the building and counter-measures had to be taken.

The new first floor was supported by arches in rooms 6, 7, 17 and 19-21. The two arches in hall 19-21 are huge. A pier in the centre of hall 17-18 must have carried beams. Staircase 9 was rebuilt. Behind the staircase a small room (11) was created. The alley was closed off at the north end by room 29, which has a barrel vault. Five piers were set against the east facade, and another five opposite these, across the street, against the Grandi Horrea. The piers obviously supported east-west running arches, and stabilized the building.

Phase 4: later third century and undated alterations

Some further alterations have been dated to the later third century (opus latericium and vittatum), other alterations could not be dated. Basins were installed in rooms 26 and 28. Room 27 is spanned by two high arches, that cannot be dated, even though one of the piers is Antonine. The piers further stabilized the building. Another basin was built in room 21. Seven very large windows were hac