Its oldest parts, the apse and choir, were built during the later part of the 12th century, by the Order of Saint John and dedicated to the Order's patron saint.
During the same century, the original wooden ceiling was also replaced with the current, star-shaped vaults.
The sacristy of the church was also built during the same time, and serves as a support for the northern wall of the choir.
[1] The building material of the church is mainly grey sandstone, used exclusively in the choir and apse.
The murals, which depict saints, the four evangelists and the devil, are located mainly in the choir.