 The castle was initially held by the Lancastrians, and the castle's constable, Sir Ralph Babthorpe, died at the Battle of St Albans in 1455, fighting for the Lancastrian Henry VI.The castle formed part of a sequence of fortifications protecting the eastern route into Scotland, and in 1461 King Edward IV attempted to break the Lancastrian stranglehold on the region.Sir Ralph Percy, one of the joint constables, defended the castle until September 1461, when he surrendered it to the Yorkists.