Stock Photo - Sailors 'Yasumi'. William Francis Forbes-Sempill, 19th Lord Sempill AFC, AFRAeS (1893-1965) was a Scottish peer and record-breaking air pioneer who was later shown to have passed secret information to the Imperial Japanese military before the Second World War. In 1921, Sempill led an official military mission to Japan that showcased the latest British aircraft. In subsequent years he continued to aid the Imperial Japanese Navy in developing its Navy Air Service and began giving military secrets to the Japanese. Although his activities were uncovered by British Intelligence, Sempill was not prosecuted for spying and allowed to continue in public life.