The first church was built in 1200 A.D. and since then it has been rebuilt three times. The church today, dating since 1834, is a three-aisle basilica and is decorated with great icons. Among them is the icon of "Lady of Hope", which the Catholics of Syros worship.
In 1652 it became Metropolis. Bishop Andreas kargas and his secretary were beheaded by the Turks in 1617. Then most of the Episcopate Archives were destroyed. The material that was saved has been kept since then in the Historic Studies Centre of the Catholic Episcopate, where there are very important documents referring to the history of the island.