The convent's first stone was laid on 5 September 1623, on land generously donated by Cateri's three inhabitants. An official ceremony was held to mark the occasion. The building overlooks the entire Aregno plain.
Its location had been chosen two years earlier, on May 6, 1621, and materialized by a cross placed on the ruins of a former commandery.
In all, it took two centuries and constant work to complete this imposing building of over 1500 m².

It consists of around 40 rooms, a cloister and a church; the latter was at that time the parish church of Cateri.

In 1642, the population of the convent was very important and many cultures were developed in its dependencies; consequently, the water requirements have, in fact, increased.
This is the reason why the neighboring municipality, Lavatoggio, was asked to donate water.

The municipality donated water from the "Capu di Guestia è Monacu Mortu" to the convent. 9 years later, another donation of water from Quarciolu and Parnicale was made; however, this water was only available from mid July to the end of October.

In 1789, the convent of Marcassu was declared National Property and sold at auction to Joseph Salvini de Nessa after the expulsion of the Franciscan friars who occupied it.

In 1806, Joseph Salvini sold the 2 large bells (bought by the factory of Sant Antonio) and the organs. He also ceded the polychrome marble high altar which now adorns the Church of Cateri.