The first news about the presence of a cathedral dates back to the 12th century, when there was a church dedicated to St. Peter the Apostle. The building was not large enough to contain a large number of believers, so a century after its construction was demolished to make room for a new building, which resisted until the Napoleonic era. The new building was dedicated to San Marco and was ruled by the Dominican order.
In 1797 the church was confiscated by Napoleon Bonaparte and his troops, who made it their headquarters; soon it became necessary to demolish the structure, for military reasons. The reconstruction works lasted from 1807 to 1810; important interventions were necessary, supervised by the architect Cristoforo Vallizzone. The new building had completely lost its original Gothic connotations, assuming a neoclassical appearance. The Cathedral of Alexandria, at the time of its reopening in 1810, was confirmed to be the one dedicated to St. Peter and St. Mark. The facade of the sacred building was completed only in 1820; interesting are the frescoes that symbolize the life of St. Peter the Apostle. The decorations inside the building were made in the twenties of the last century. There are several works of interest inside the building.