Baynes was educated at Leighton Park School (along with two other leading members of the British Psychoanalytical Society: John Rickman and Lionel Penrose) and then at Trinity College, Cambridge, where he read medicine and where he won Blues for Rowing and Swimming two years running.

Agnes (known as Anne) and Peter married and had three further children Michael, Jeremy (known as John) and Diana.

He volunteered to serve in the First Balkan War (1912-1913) and was head of the Red Crescent mission to Turkey and was decorated by Enver Pasha.

That year he started collaborating with Cary Angulo, née Fink (1883-1977) in translating Jung.

[8] On his return to the UK, he became one of the chief proponents of the new psychology, and leader of the London club, while others emigrated.