in 1796, coleridge wrote his poem "kubla khan" — along with the "ancient mariner", it is his best-known work. at about the same time, in the later 1790s, coleridge became addicted to opium. at that time the drug was legal, and was widely used as a painkiller. coleridge's addiction to opium marked the rest of his life. his health suffered, and he had trouble supporting his wife and children. he also had a hard time finishing the writing projects he started.