He received international acclaim for his discoveries in relation to blood coagulation, causes of abnormal bleeding, and causes of thrombosis.
He played a key role in identifying the role of anticoagulants and antiplatelet agents in preventing heart attacks, setting a modern benchmark for the treatment of heart disease.
He was born in Elgin in northern Scotland on 2 October 1921 and was the son of Robert Douglas (1871–1948), a crofter.
From 1945 to 1948 he served as a Major in the Royal Army Medical Corps in the post-war re-establishment of Palestine and was Mentioned in Dispatches.
[2] After this period he worked in the Blood Coagulation Research Unit in Oxford with Robert Gwyn Macfarlane.