Kirby Muxloe Castle was built by William, Lord Hastings, the chamberlain of the royal household and a favourite of Edward IV. William had acquired extensive estates across the Midlands during the Wars of the Roses, much of it confiscated from his enemies. William's father, Sir Leonard, had maintained his seat at Kirby Muxloe, but William moved his own seat to the manor of Ashby de la Zouch in 1462. In 1474, Edward granted William the right to crenellate, or fortify, four of his manors and to build deer parks around them. Among these was Kirby Muxloe, which the King authorised to be turned into a castle and surrounded by a large park of .