Dedicated to the patron saint of the Venetians, Agios Markos Basilica was built at the beginning of the Venetian rule in 1239, right opposite the fountain on Lions Square, in order to establish their dominance quickly over the new colony. At the same time, however, it was a demonstration of love and gratitude for their country.
One of the most important Venetian buildings in the capital of the prefecture, it was built with plain plan view and covered entrance, while the original form was not very different from what it is today. The Society of Cretan Historical Studies had the monument restored in 1956, preserving its original form as much as possible.
The bell tower of the church was a copy of that of Saint Markus church in Venice, and it was destroyed during the Ottoman rule only to be replaced by the minaret of Defterdar Mosque which the church was turned into. After the end of the Ottoman rule, the residents of Heraklion tore the minaret down in order to erase the painful memories related to the occupation.