According to recent study , in the exact spot in which the palace exists today , there was the foundations of the ancient temple of the Sun-god ' Helios ' and probably that was the spot where Colossus of Rhodes stood in the Antiquity . The palace was originally built in the late 7th century as a Byzantine citadel . After the Knights Hospitaller occupied Rhodes and some other Greek islands ( such as Kalymnos and Kastellorizo ) in 1309 , they converted the fortress into their administrative centre and the palace of their Grand Master . In the first quarter of the 14th century , they repaired the palace and made a number of major modifications . The palace was damaged in the earthquake of 1481 , and it was repaired soon afterwards
earthquake of 1481
1481 Rhodes earthquake
Palace of the Grand Master of the Knights of Rhodes