The original square form castle in Ivry-la-Bataille was built around 960 AD. It was 32x25m wide stone building with a small chapel. Today the first floor of this castle remains and it is the oldest medieval building in Normandy. The castle was enlarged during the next centuries. In the Hundred Years' War it was conquered by English (1418), but moved back to the hands of French (1424). After 1449 the castle was left to decay. The restoration began in 1968.
References:Celje Castle was once the largest fortification on Slovenian territory. The first fortified building on the site (a Romanesque palace) was built in the first half of the 13th century by the Counts of Heunburg from Carinthia on the stony outcrop on the western side of the ridge where the castle stands. It had five sides, or four plus the southern side, which was a natural defence. The first written records of the castle date back to between 1125 and 1137; it was probably built by Count Gunter. In the western section of the castle, there was a building with several floors. Remains of the walls of this palatium have survived. In the eastern section, there was an enclosed courtyard with large water reservoirs. The eastern wall, which protects the castle from its most exposed side, was around three metres thicker than the rest of the curtain wall. The wall was topped with a parapet and protected walkway.