Geoffrey Basil Spicer Simson was born in Hobart, Tasmania, on 15 January 1876, one of five children. His father, Frederick Simson, had been in the merchant navy and was a dealer in gold sovereigns in India who eventually settled in Le Havre, France, at the age of thirty-one. There he met eighteen-year-old Dora Spicer, daughter of a visiting English clergyman, William Webb Spicer, and on marrying changed his name to Spicer-Simson. In 1874 the Spicer-Simsons moved to Tasmania, where they had some family, and ran a sheep farm for five years. Though Geoffrey was born in Tasmania, he soon moved to France at his mother's wishes. He and his siblings were sent to schools in England. The eldest, Theodore Spicer-Simson, became a world-famous medallion portrait artist, moving between France and the United States. His youngest brother, Noel, eventually joined the British Army.