John married Joan of Bar but lived adulterously with Maud de Nereford from a village near Castle Acre in Norfolk.He was initially not well-received, but an Act of Accord made in October 1460 recognised him as heir to the throne and named him Protector of the Realm.During the English Civil War Sandal Castle was Royalist, although its neglected state left it out of the major conflicts.Butler recounts:[6] Having been assured that they would receive a safe passage to Welbeck House in north Nottinghamshire they surrendered the castle at 10 o'clock on 1 October 1645.The castles built by William the Conqueror's followers were self-sufficient strongholds, some of which were tax-gathering points, some controlled the larger towns, river crossings or passes through hills.The first castles were probably started and completed in the early 12th century by William de Warenne, 2nd Earl of Surrey after he had been granted the manor of Wakefield by Henry I. Sandal and Lowe Hill were motte-and-bailey earthwork castles with wooden towers on the mound and baileys with timber palisades and deep ditches.[7] Only Sandal survived and during the 13th century the keep, curtain wall and other buildings were rebuilt in stone, probably started by either the sixth or seventh Earls Warenne.This project started as an experiment in adult education, but with the help of over a hundred local volunteers it grew into a complete and rigorous excavation that continued for nine years.Whilst excavating the bailey, archaeologists found remains of flint tools suggesting a Mesolithic encampment was there in about 5,000 BC.There have been historical re-enactments and "living history" days, including commemoration of the Battle of Wakefield and the deaths of Richard Duke of York and his son Edmund.In February 2015 Wakefield Council announced that due to budget constraints they were considering plans to either close the visitor centre or reduce its opening hours.The castle is a Scheduled Monument,[16] which means it is a "nationally important" historic building and archaeological site which has been given protection against unauthorised change.