The site of the convent encloses millenary remains. It was founded by king Desiderio in 753 A.D. Nowadays, the superimposition of buildings on the foundations of old ones is evident from the mosaics of the old Roman villa,
the Lombard Basilica of S.Salvatore, the Renaissance church of Santa Giulia.
In the church of Santa Maria in Solario, with frescoes by Floriano Ferramola, under the cupola, the "Treasure of Santa Giulia" is displayed. The most important items are: the Great Cross of king Desiderio, covered in jewels and cameos and the Lipsanoteca, a VIth century ivory reliquary case.