Haydar Pasha Mosque, the former church of St. Catherine, was built in the 14th century and it follows the southern France architectural style. The church is an elegant building comprised of a central space covered by two groin vaults. It also has an altar which ends with a three sided apse. On the apse’s northeastern side there is a two-storey building with groin vaults. On the apse’s southwestern side there is a small circular tower with a staircase. This tower has been turned into the mosque’s minaret. Of special interest are the building’s three-sided support pillars that are interrupted by oblong windows.
Three entrances lead to the church’s interior. The largest entrance is located at the centre of the west wall and the other two in the west part of the north and south wall. All three entrances are decorated with rich relief decoration and there is a round window (rosette) above the west entrance.
With the island’s conquest by the Ottomans this church was turned into a mosque and named ‘Haidar Pasha mosque’.
References:The Walls of Constantinople are a series of defensive stone walls that have surrounded and protected the city of Constantinople (today Istanbul) since its founding as the new capital of the Roman Empire by Constantine the Great. With numerous additions and modifications during their history, they were the last great fortification system of antiquity, and one of the most complex and elaborate systems ever built. They were also the largest and strongest fortification in both the ancient and medieval world.
Initially built by Constantine the Great, the walls surrounded the new city on all sides, protecting it against attack from both sea and land. As the city grew, the famous double line of the Theodosian Walls was built in the 5th century. Although the other sections of the walls were less elaborate, they were, when well-manned, almost impregnable for any medieval besieger.