William Ernest Henley was an English poet, literary editor and critic who lost a leg to tuberculosis of the bone as a young man and spent long stretches in hospital. He wrote “Invictus” in 1875 while recovering from surgery at the Royal Infirmary of Edinburgh; its defiant self-mastery grew directly out of that ordeal. Robust and bearded, he was also the model for his friend Robert Louis Stevenson’s Long John Silver.