Wickham was born on the island of Hobopeka in the New Georgia region of the Solomon Islands. He was the son of Frank Wickham, an English plantation owner, and Ameriga a Melanesian woman from Buin, Papua New Guinea. He was jointly raised by his parents and the local ceremonial and war leader Chief Hingava. His only known formal European style education was at Newington College in Sydney from 1899 until 1900. A few years later Wickham was joined in Sydney by his younger half-brother Alick Wickham who gained attention with his swimming stroke in an under-10s race at Bronte Beach. Following Wickham’s return to the Solomons, he managed a copraplantation at Hobopeka in the Roviana Lagoon, and worked as an accountant for Burns Philp. He served as a lieutenant during the Japanese occupation of The Solomons during World War II. He married six times and fathered several children. He died in the Solomons and is buried there.