The origins of the abbey are rather contentious and not fully validated by written records. However, tradition has it that the hermit Alemanno settled in the area in the year 800 to find peace of soul and construct an oratory and a cell. This atmosphere of spiritual tranquillity attracted an increasing number of the faithful, the number of cells increased such that the oratory became a monastery for which Canons Regular of Saint Augustine were called upon to head.
In 1070 the church dedicated to Saint Peter was inaugurated. In 1090 the monastery of Rosazzo was elevated to the status of abbey and in the following year Augustinian rule was suppressed and replaced by Benedictine rule.
In the Middle Ages the Abbey of Rosazzo took on an important economic function in addition to its role of spiritual guidance.
Later, during the battles between Aquileia and Cividale, between Venice and the imperialists, the monastery was transformed into a defensive stronghold. After more than 300 years the Benedictine monks left the abbey, which from 1423 to 1751 (year of the suppression of the Patriarchate of Aquileia) was governed by commendatory abbots, whose coat of arms can still be seen in the fanlights of the cloister. During this period, in 1522 the Dominicans established themselves in the abbey and remained for 248 years.
Following a number of wars and raids, a fire in 1509 completed the ruin of the abbey. Only twenty years later the rebirth of the abbey complex began thanks to the work of the commendatory abbot Giovanni Matteo Giberti, who availed himself of the assistance of the architect from Cividale, Venceslao Boiani.
In 1823 the bishop Emanuele Lodi transformed the abbey into the summer residence of the bishops of Udine. The bishop of Udine was conferred the noble title of Marquis of Rosazzo, a title which in 1927 was also recognized by the Kingdom of Italy.
The structural renaissance of Rosazzo was largely due to the emeritus archbishop of Udine, mons. Alfredo Battisti and his interest in including the building among the reconstruction works following the 1876 earthquake.
The spiritual renaissance was inspired by "Project Rosazzo", which was launched on 1 October 1994.
Today the "monastery of the roses" operates as a cultural centre, a humanistic and social meeting place and a venue where conferences, seminars, exhibitions and debates are organized.