The earliest material evidence is from 1303, the year in which Bishop Tedisio had an oratory built dedicated to St. Andrew, of which the Gothic portal that leads into the present great chapel of the Episcopio remains.
In 1427 the palace was enlarged by Bishop Pietro Spano, under whose episcopate the transfer of the episcopal see and cathedral from Torres to Sassari took place. In this text it is said that Sassari “habet decens palatium.” Enrico Costa states that Archbishop Giovanni Sanna enlarged the building in 1571 and affixed his coat of arms at the entrance, in what is now largo Porta Nuova. It was Archbishop Andrea Manca y Zonza, between 1644 and 1652, who carried out works in which the central loggia and portico were built on the ground floor, where until 1906 there was a ramp for carriages leading to the entrance of Largo Porta Nuova.
A new major restoration dates back to April 1919, during the episcopate of Archbishop Cleto Cassani, in which the current conformation of the Palace was arrived at.
In 2024, commissioned by the current Archbishop Monsignor Gian Franco Saba, the latest restoration work was completed. The interventions, carried out on the two main levels, Aimed at opening and returning cultural and social spaces to the city, involved the reception rooms, the loggia and some private spaces that were re-functionalized into a library and archive.
