Douglas, Archibald, fourth earl of Douglas, and first duke of Touraine in the French nobility (c.1369–1424) (Oxford Dictionary of National Biography)

Scottish nobleman and commander in the wars against the English in the early fifteenth century. Douglas was captured by Sir Henry Percy at the Battle of Homildon Hill in 1402 and taken prisoner by the English king in 1403 after fighting in a battle with his captors against the king, not to be released until 1413.

D'Israeli, Isaac, 1766-1848

A British writer, essayist, and scholar, Isaac D'Israeli created such works as Curiosities of Literature (1791) and The Literary Character of Men of Genius, Drawn From Their own Feelings and Confessions (1818), a revision of An Essay on the Manners and Genius of the Literary Character (1795).