James Bagot Oldham was born in Belfast on 7 November 1899, the first child of Samuel Charles Oldham, a ship repair director and of his wife Kathleen, née O'Flaherty. Most of his father's family were in the medical profession. He was cousin to Sir Hugh Rigby FRCS, Sergeant-Surgeon to HM George V.

Frederick Herman Aitken Walker, the only child of Frederick, a cotton manufacturer, and of Edith Walker, was born on 1 July 1900 at Clayton Le Moors, Lancashire. He was educated at Calday Grange School, West Kirby, Cheshire, and, after one year as a medical student at Liverpool University he moved t