Graham Higman was a highly talented mathematician whose principal field of research was group theory. He played a key role in the development of this field, and is regarded as one of the three most significant British group theorists of the 20th century, alongside William Burnside (FRS 1893) and Philip Hall (FRS 1951). He studied at Oxford, gaining a doctorate under the supervision of Henry Whitehead (FRS 1944). After working for the Meteorological Office during the Second World War, he was appointed to a position at the University of Manchester in 1946, and subsequently at Oxford. In 1958 he was elected FRS, and in 1960 he was appointed to the Waynflete professorship in mathematics at Oxford, a position he held until his retirement in 1984. His research was significant and influential. Highlights include his work on embeddings of groups, including ‘HNN-extensions’ and their application in the famous Higman Embedding Theorem, and his constructions of a finitely-presented group that is isomorphic to a proper factor of itself, and a finitely-presented infinite simple group. Some of his work also played an important role in the proof of the Odd Order Theorem and a solution to the restricted Burnside problem. He and his wife Ivah were dedicated Methodists, and Graham was a keen bird-watcher. He was also well known for his view that pure mathematics should be studied for its beauty and its life-affirming properties, for the non-standard yet highly supportive way he supervised his students and for his somewhat mischievous sense of humour.