Ivor John Thomas qualified from the London Hospital in 1942 and within three years had obtained both Edinburgh and English Fellowships. During the latter years of the war he was resident surgical officer at Cardiff Royal Infirmary, assistant surgeon in the Emergency Medical Service and surgical regi

He was born in London in 1912, and received his early education at Doon House Preparatory School, Westgate-on-Sea, Kent. He then went to Uppingham and was promoted to the scientific sixth form in his fourth year. In 1930 he was enrolled as a medical student at the London Hospital Medical College.