History of York

William the Conqueror had two castles built following his march into the city in 1068.

The main one is on the site now occupied by York Castle Museum and Clifford's Tower.

Norman castles were generally built to a standard design called a motte and bailey.  A simple wooden building - the tower or keep - was put at the top of a large mound or motte.  This is the mound that Clifford's tower sits on today.

At its foot was a fenced off and defended larger area with many more buildings such as workshops and stables.  This was the bailey.  

In the case of York Castle it's now quite difficult to spot the extent of bailey, though on two sides it is defined by the rivers.  The bailey area includes the grounds of York Castle Museum and the square in front of it.

The Norman castle was the scene of rebellion and revenge almost as soon as it was built. 

The keep was the supposed place of government and safety that jews retreated to in 1190 before the massacre.  That awful event ended with the keep being burnt down.  It was rebuilt in 1194, again in wood.