Gordon Marshall Petersen, a member of the London Mathematical Society from 1958, was born on 25 November 1921 in San Francisco, and died on 9 November 1996 in Christchurch, New Zealand.

His father was Danish, born in 1883 in Esbønderup, a village on the island of Zealand. While still only 15, he suddenly announced to his family that, having secretly saved up his fare, he was emigrating to America the next day. He had little formal education, but was able to support his family comfortably. One day during the Depression, father and son, in their shabbiest clothes, visited a Cadillac showroom and were about to be ejected when the father produced a paper bag stuffed with enough banknotes to buy the car they had been inspecting. No wonder Gordon, an only child, adored his father!

Gordon's mother Catherine was born in 1883 in America to Richard and Ann Marshall, who had not long before emigrated from Nottingham in England. She had three older siblings and also a younger brother, Gordon, who operated several garages and built his own aeroplanes. He survived the First World War in the US Army Air Force, but was killed in an air crash in 1920, at the age of 32.