Doyle was a supporter of the campaign for the reform of the Congo Free State that was led by the journalist E. D. Morel and diplomat Roger Casement. In 1909 he wrote The Crime of the Congo, a long pamphlet in which he denounced the horrors of that colony. He became acquainted with Morel and Casement, and it is possible that, together with Bertram Fletcher Robinson, they inspired several characters that appear in his 1912 novel The Lost World.[68] Later, after the Easter Rising, Casement was found guilty of treason against the Crown, and was sentenced to death.