Donald Manton Llewelyn was a paediatric surgeon at the Prince of Wales Hospital, Sydney. He was born in Sydney on 11 December 1929, the sixth child and fourth son of Arthur Stuart Llewelyn, an insurance executive, and Loys Llewelyn née Bartrim, the daughter of a farmer. He was educated at Roseville

Warwick John Cook was a consultant general surgeon at Liverpool Hospital, Sydney, New South Wales. He was born in Sydney on 3 July 1930. His father Marcus Cook was a service manager; his mother Hilda Maude Cook née Thame was a housewife. He had a sister, Nerida. He attended Sydney Boys’ High School