Mystras, the ‘wonder of the Morea’, developed down the hillside from the fortress built in 1249 by the prince of Achaia, William II of Villehardouin, at the top of a 620 m high hill overlooking Sparta.
The Principality of Achaea was one of the three vassal states of the Latin Empire which replaced the Byzantine Empire after the capture of Constantinople during the Fourth Crusade. It became a vassal of the Kingdom of Thessalonica, along with the Duchy of Athens, until Thessalonica was captured by Theodore, the despot of Epirus, in 1224. After this, Achaea became for a while the dominant power in Greece.
The Franks surrendered the castle to the Byzantines in 1262, it was the centre of Byzantine power in southern Greece, first as the base of the military governor and from 1348 as the seat of the Despotate of Morea. Captured by the Turks in 1460, it was occupied thereafter by them and the Venetians.
Today impressive ruins of Villehardouin's Castle still remain.
References:Krickenbeck moated castle is one of the oldest on the lower Rhine. Its history dates back to the year 1104, when the castle was first mentioned. It is unclear why the old castle, which was certainly inhabited by Count Reginar, was abandoned or destroyed. In the mid-13th century the castle was moved to the current location. At the end of the 14th century the new castle belonged to the Counts of Kleve.
Johann Friedrich II of Schesaberg converted the castle into a Baroque mansion between 1708-1721. On September 7, 1902, a fire destroyed the entire mansion. From 1903 to 1904, a three-winged castle was built in the Neo-Renaissance style. Today Krickenbeck is a conference center.