The Duke of Windsor (1894 - 1972), who reigned briefly as King Edward VIII in 1936, as a boy, holding his baby brother Prince George, Duke of Kent, 1902 - two future kings (one born to the throne, the other never expecting it).
King George V, 1895: George, a grandson of Queen Victoria and cousin to Tsar Nicholas II, was given the title Duke of York in 1892. A year later he had married Princess Mary of Teck. Together they lived quietly in York Cottage at Sandringham. By the age of 30, he had young boys, Edward and Albert.