Lord Francis Douglas Marquess of Queensberry; a younger brother, Lord Archibald Edward Douglas (1850–1938), who became a clergyman; and a younger brother and sister, the twins Lord James Douglas (d. 1891) and Lady Florence Douglas (1855–1905), who married Sir Alexander Beaumont Churchill Dixie, 11th Baronet. He was an uncle of Oscar Wilde's lover Lord Alfred Douglas, and a younger brother of John Douglas, 9th Marquess of Queensberry. In 1858, Douglas's father, Lord Queensberry, died in what was reported as a shooting accident, but his death was widely believed to have been suicide. In 1862, his mother, Lady Queensberry, converted to Roman Catholicism and
Lord Alfred Douglas stock market raid and no present of fine furniture". In 1924, while in prison, Douglas, in an echo of Wilde's composition of "De Profundis" (Latin for "From the Depths") during his incarceration, wrote his last major poetic work, "In Excelsis" (In the Highest), which contains 17 cantos. Since the prison authorities would not allow Douglas to take the manuscript with him when he was released, he had to rewrite the work from memory. Douglas maintained that his health never recovered from his harsh prison ordeal, which included sleeping on a plank bed without a mattress. Following his incarceration in 1924,