Geoffrey Taylor Bull was an English Christian missionary and author. Bull was born in Eltham, SE London, into a family, William and Ethel, with conservative evangelical beliefs. At 15 years old, he was baptised and received into the fellowship of a group of Christians meeting in "New Testament simplicity". This group was of the Open Brethren persuasion. His original ambition for a career was to enter banking, but by 1941 he became absorbed with missionary work in Central Asia.