From its initial construction in 1239 until 1956, when restoration work began, the monument underwent numerous alterations. These were necessitated both by natural disasters, such as the earthquakes in 1303 and 1508, and by historical changes linked to the various uses to which the building was put in different eras.

The church was originally a three-nave basilica with a timber roof and raised central nave, divided by two rows of columns bearing gothic arches. The portico consisted of six columns linked by five arches. The monument regained this form after restoration in 1956.

Part of the Venetian base for the bell tower and the Turkish minaret that later rested upon it still survive.