Under Henry III, Richard, the 1st Earl of Cornwall was formally granted the castle as his main residence in 1231. Richard lived in considerable style, and spent substantial sums on the property, building a new hall and more luxurious fittings. Richard's election as King of the Romans in 1251 brought an end to his use of the property, but the castle became embroiled in the Second Barons' War in the 1260s. Simon de Montfort seized the castle after his victory at the battle of Lewes, using it to imprison the royal family for a time, before moving them to the more secure Kenilworth Castle. Reclaimed by Henry III at the end of the conflict, it continued to be used by the Earls of Cornwall as a luxurious home for the rest of the century.