 In 1735 he purchased the manor of Astrop, Kings Sutton, Northamptonshire where he built a new mansion Astrop House, (now a Grade II* listed building).In 1737 he was elevated to become Chief Justice of the Court of Common Pleas, the third most senior judge in the English legal system as it then existed, and held this post until his death in 1761; at the same time he was appointed to the Privy Council.By his wife Margaret Brewster Willes had four sons and four daughters.