East of Splatzia Square of the old city of Chania is located the church of Agios Nikolaos, which was built before 1320, during the Venetian Period, as monastery of Dominican Order.
During the Venetian period it constituted the most important church of the city. It was elegant and big in capacity, with wide arches in the interior. After the predominance of Turks in Chania the temple was turned into mosque and was named Hiougkar Tzamisi (mosque of the Emperor), in honour of the sultan of Ottoman Empire, Imbraim.
Its importance is highlighted by the existence of two- instead of one- balconies on the minaret. In 1928, after being seized by the Christians orthodoxe, the mosque was turned into a christian church and has been dedicated to Agios Nikolaos.
Source: chaniatourism.com