The great Imperial palace where Helen, the mother of Constantine, lived following the victory at the Milvian Bridge (312A.D.) is still little known. She created this palace by altering and enlarging the residence that had belonged to the Severan emperors a century earlier. In particular, Heligobalus had built imposing structures for games known as the Anfiteatrum Castrensis and the Circus Varianus. Of the residence itself, known in the Christian sources as the Sessorium, remain the aula, converted into a chapel to house the Cross, the great absidal hall wrongly known as the Temple of Venus and Cupid and the substantial remains of a number of domus with mosaics and frescoes. The scant remains of the Severan baths, which were restored by Constantine’s mother, do not seem to have belonged to the Imperial property but were for public use. The successive transformations of this complex and the partial conservation of the archaeological site are the work of the Carthusian and Cistercian orders. In the post-unification period the site became a military property where the “Umberto I Principe di Piemonte” garrison was built. Recent financing for the Jubilee year paid for the demolition of all illegal and degrading structures on the site, the restoration of some of the most important elements from antiquity and the recovery of the ex-garrison service buildings which will house the new museum of the Soprintendenza Archeologica di Roma. The so-called Temple of Venus and Cupid and the mosaic pavements of the two Constantinian domus have been restored and consolidated. Trenches excavated up against the Acqueduct brought to light other domus of Roman date, whilst outside the complex in Piazza S. Croce and in via Eleniana the remains of the façade of an Imperial palace have been uncovered. A previous excavation on the site of the Anfiteatrum Castrensis, within the Garden of the Cistercian Convent, had already revealed the precision of Palladio’s drawings and shed new light on the technical characteristics and perfection of this building’s architectural forms. (Mariarosaria Barbera)

This contribution (cf. FOLD&R 2008, nn. 124 e 125) updates knowledge regarding the ancient monuments present in the area of S. Croce in Gerusalemme, with new data which emerged following finds made during work on urban reorganisation and on the basis of research undertaken in the historical archives of the Archaeological Superintendency of Rome and the Municipal Superintendency of Rome. It gives a general picture of the topography of the villa of the _Horti Spei Veteris_, built in the Severan period, which became the _Palatium Sessorianum_ under Constantine. Begun by _Septimius Severus_ and enlarged by Caracalla, the project reached its final form under _Helagabalus_, when the _Horti_ appeared as a villa comprising monumental nuclei – including the _Amphitheatrum Castrense_ and the _Circus Varianus_ – which were linked by a _porticus triumphi_. The next chapter deals with the new data relating to the cavea on the right hand side of the Varian Circus. Chapter three looks at various elements sporadically investigated on several occasions and in varying circumstances, which for the first time are reconstructed as a single unit and identified as part of a _porticus triumphi_. This was a very particular type of monumental building created for a public function during the late Republican period and later privatised. The recent restoration of the Helenian Baths brought to light architectural elements, previously unknown, which have led to a more complete reconstruction of the north-eastern side of the monument. These elements constituted a sort of monumental entrance for the whole bath complex, which was almost certainly for public use and separate from the imperial residence. The following chapter describes a residential quarter situated between via Eleniana and the Aurelian Walls. Four _domus_, dating to between the mid 2nd and the beginning of the 4th century A.D., formed part of this quarter and have been reconstructed using archival material and excavation data. The final chapter is dedicated to the public sector of the _Palatium Sessorianum_, of which parts of a public triclinium and a link corridor have been found.