The creation of the abbey is generally connected with the large donations from marquis
Aimeric of Mantua, in the 950s, followed by others from
Hugh of Tuscanya few years later. The abbey is mentioned as still in construction in a document from 993. It became an independent fief in 996 and, around 1000, the abbey received the status of
diocese directly subject to the
Holy See. The independence was confirmed by emperor
Frederick Barbarossa in 1177 and by Pope
Celestine III in 1196. In 1213 the abbey adhered to the
Camaldolese order, dedicating itself in particular to cultural activities: it amassed a large library and included a school of philosophy, theology, chant, arts and sciences, although it got progressively detached from the care of the territory and from its colonists, which had been the base of its richness in the previous centuries. In the early 15th century the abbey lost its temporal rights, and was put under the
in commendam status, i.e. under the control of external ecclesiastics. Its
lay abbots include Pietro Ottoboni, the future
Pope Alexander VIII. A seminary was founded in 1747. The
Republic of Venice suppressed it on 11 April 1789 and seized its asset; the diocese was also suppressed in 1792, its twelve parishes being moved to the
diocese of Adria. It was partially demolished from 1810, when the complex was under French control. ==Description==