Born into poverty as an illegitimate London child, Wallace left school at age 12. He joined the army at age 21 and was a war correspondent during the Second Boer War, for Reuters and the Daily Mail. Struggling with debt, he left South Africa, returned to London, and began writing thrillers to raise income, publishing books including The Four Just Men (1905). Drawing on his time as a reporter in the Congo, covering the Belgian atrocities, Wallace serialised short stories in magazines such as The Windsor Magazine and later published collections such as Sanders of the River (1911). He signed with Hodder and Stoughton in 1921 and became an internationally recognised author.
