He was born into a wealthy London family, the son of Col. William and Elizabeth (née Sloan) Sotheby, and was educated at Harrow School and the Military Academy, Angers, France before joining the army at 17, where he served for six years until his marriage in 1780, when he devoted himself to literature.
His wealth enabled him to play the part of patron to many struggling authors, and his friends included Walter Scott, Byron, Wordsworth, Coleridge, Robert Southey, Arthur Hallam, and Thomas Moore.
[1] He published a few dramas and books of poems that had limited success; his reputation rests upon his translations of the Oberon of Christoph Martin Wieland, the Georgics of Virgil, and the Iliad and Odyssey by Homer.
"[3] His 1801 play Julian and Agnes was acted at the Theatre Royal, Drury Lane with John Philip Kemble and Sarah Siddons in the lead roles.
Joanna Baillie, a close friend of Sotheby's for "nearly thirty years" mourned his death: "A more generous, high-minded, amiable man never lived, and this, taken together with his great talents & acquirements, makes a Character which cannot be replaced.