The Basilica of San Pietro di Castello, located on the ancient island of Olivolo (now called Castello, from which it takes its name), was an independent episcopal seat from the patriarchate of Grado for almost seven hundred years, from 775 to 1451, and subsequently a cathedral and patriarchal seat until 1807, the year in which the title passed to St. Mark.
Initially the Church was dedicated to the Byzantine saints Sergio and Bacco and dated back to the 7th century; over the years, towards the 9th century, Bishop Magno built a group of "mother" churches including this one which he dedicated to Saint Peter the Apostle.
The current forms of the Church are the result of the works carried out between the end of the 16th and the first thirty years of the 17th century. The renovation of the facade, carried out by Francesco Smeraldi, is the completion of the previous project by Andrea Palladio from 1556.
