Jonathan Philip Chadwick Sumption, Lord Sumption,, is a British author, medieval historian and former senior judge who sat on the Supreme Court of the United Kingdom between 2012 and 2018. Sumption was sworn in as a Justice of the Supreme Court on 11 January 2012, succeeding Lawrence Collins, Baron Collins of Mapesbury. Exceptionally, he was appointed to the Supreme Court directly from the practising Bar, without having been a full-time judge. He retired from the Supreme Court on 9 December 2018 upon reaching the mandatory retirement age of 70.