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 of by the friends and families of both men. During the later part of 1897, Wilde and Douglas lived together in Naples, but because of financial pressures and for other personal reasons, they separated. Wilde spent the remainder of his life primarily in Paris, and Douglas returned to Britain in late 1898. The period when the two men lived in Naples would later become controversial. Wilde claimed that Douglas had offered a home, but had no funds or ideas. When Douglas eventually did gain funds from his late father's estate, he refused to grant Wilde a permanent allowance, although he