The site has remained in use by the Crown for nearly 1000 years - as a military base, a tax office and treasury, an administrative headquarters, a prison and a court. The Crown Court is still on the site.
The castle's history is bloody - with battles, massacres, fires, executions and burials.
Looking at the site today it can be difficult to understand the layers of the history. But large parts of the Medieval castle are still standing - most impressively some of the outer walls and, of course, Clifford's Tower.
In the 20th Century some of the former prison buildings were converted to become York Castle Museum.