Born on 25th March 1887 in Cambridge, UK, Geoffrey’s parents were John Neville Keynes, an economics lecturer at the University of Cambridge, and his wife, Florence Ada, nee Brown, a successful author and social reformer. Geoffrey was their third child - his older brother, who became an economist, was John Maynard Keynes, he had a sister - Margaret, who married the Nobel Prize–winning physiologist Archibald Hill.
Geoffrey was initially educated at Rugby School, where he became friends with the poet Rupert Brooke. Geoffrey went on to study at Pembroke College, Cambridge, where he earned a first-class degree in the Natural Sciences Tripos. He was later made an honorary fellow of Pembroke College. Geoffrey then qualified for a scholarship to become a surgeon with the Royal College of Surgeons in London. However, he delayed his medical studies to serve during the war, when he served as a Lieutenant in the Royal Army Medical Corps.
Geoffrey began his career as a physician during the First World War, before becoming a doctor at St Bartholomew's Hospital in London, where he made notable innovations in the fields of blood transfusion and breast cancer surgery.
After Rupert Brooke’s death n 1915, Geoffrey was appointed literary executor for Rupert's estate.
