John O'Connell was a consultant neurosurgeon at St Bartholomew's. He was born in Manchester on 16 September 1906, to Irish parents. His father, Thomas Henry O'Connell, was a civil servant. His mother was Catherine Mary née O'Sullivan. He was educated by the Jesuits at Clongowes and later at Wimbledo

Trained at the North Middlesex Hospital during 1930-32 as a general surgeon, he also practised neurosurgery and cardiac surgery. He became a frequent visitor to European and Russian clinics, attending surgical conferences, and was one of the early visitors to Moscow, when brain operations were carri