Albert, first duke of Prussia and last grand master of the Teutonic Knights, is known chiefly for ending the Teutonic Knights' government of East Prussia.
Louis Bourbon, Duke of Burgundy, was the grandson of Louis XIV. Incorrigible as a child, he grew up, married and fathered the next king of France.
Charles of Blois was a rival duke of Brittany in the mid-1300s.
Prince Philip, Duke of Edinburgh, is best known as the husband of Queen Elizabeth II, the father of Prince Charles, and the grandfather of Prince Harry and Prince William.
Edward VIII became king of the United Kingdom following the death of his father, George V, but ruled for less than a year. He abdicated the throne in order to marry his lover, Wallis Simpson, thereafter taking the title Duke of Windsor.
Franz Ferdinand's assassination on June 28, 1914, at the hand of a Serbian terrorist group the "Black Hand," led to the beginning of World War I.
Maurice was duke and elector of Saxony (southeastern Germany) during the 16th century.
Alexei Nikolaevich was the only son of Nicholas II, the last tsar of Russia, and the tsarina Alexandra. He was killed with his family during the Russian Revolution.
King Philip II of Spain, also known as Philip the Prudent, ruled one of the world's largest empires. The Philippines are named after him.
Prince William is the eldest son of Princess Diana and Prince Charles of Wales and is next in line for the British throne after his father.
Prince Rupert, a 17th century soldier, statesman and scientist, is best known for his talent as a Royalist commander of the English Civil War (1642 - 1651).