SESSORIUM
a building of unknown origin, situated at the extreme south- east of Region V, adjoining the amphitheatrum Castrense. It was earlier than the Aurelian wall which cut through it, but is not mentioned before that time unless the emendation Σεσσώριον for Σηστέριον in Plutarch, Galba 28, is admitted (Becker, de Romae veteris muris 120; De Rossi, Roma sotterranea iii. 408). From the beginning of the sixth century it appears as Sessorium in the Excerpta Valesiana 69 (Mommsen, Chron. min. i. 324: in palatio quod appellatur Sessorium), and in certain scholia (Pseudoacron. in Hor. Epod. 5. 100; Sat. i. 8. 11, 14; Comm. Cruq. ad locc. citt.), where paupers and criminals are said to have been buried outside the porta Esquilina or on the Esquiline in qua est Sessorium, although this building was at least 1400 metres from the gate. That part of the building which was outside the Aurelian wall was destroyed, but the extensive inner section became an imperial residence by the beginning of the fourth century, and Helena, the mother of Constantine, lived here. Hence it was called palatium Sessorianum (LP. vit. Silves. 22; LPD i. 179, 196, n. 75).Constantine converted one of the halls of the palace 1into the church of S. Croce in Gerusalemme, and placed in it the fragments of the true cross which Helena brought from Jerusalem. This hall was 34.35 metres long, 21.75 wide and 20 high, with five open arches on each side and windows above, and resembled closely the so-called templum Sacrae Urbis of Vespasian both in construction and scheme of decoration. Constantine walled up the arches and added the apse at the east end, but the columns were not set up until the eighth century. North of the church are the remains of another hall of the Sessorium, consisting of the apse with external buttresses, added almost immediately after its construction, and the start of the nave, probably belonging to the time of Maxentius (Ill. 49). This hall was intact down to the sixteenth century and was erroneously called templum Veneris et Cupidinis (RA 147-152). In 1887 further remains of a building of about 100 A.D. were found on this spot (NS 1887, 70, 108; BC 1887, 100). For further description of the Sessorium, see LR 399; Ann. d. Inst. 1877, 371 ; Mon. L. i. 490-492; HJ 249-250; LS iii. 163-164; Arm. 795-800; Becker Top. 556-557; SR i. 248; HCh 243; BC 1925, 278.