Peter III of Russia
Empress Elizabeth arranged for Peter to marry his second cousin, Sophia Augusta Frederica (later Catherine the Great), daughter of Christian August, Prince of Anhalt-Zerbst and Johanna Elisabeth of Holstein-Gottorp. The young princess formally converted to Russian Orthodoxy and took the name Ekaterina Alexeievna (i.e., Catherine). They married on 21 August 1745. The marriage was not a happy one but produced one son, the future Emperor Paul, and one daughter, Anna Petrovna (20 December 1757 – 19 March 1759). Catherine later claimed that Paul was not fathered by Peter: that, in fact, they had never consummated the marriage. During the sixteen years of their residence in Oranienbaum, Catherine took numerous lovers, while her husband did the same in the beginning.
Catherine of Austria, Lady of Coucy
At the age of 18, Catherine married her first husband Enguerrand VI, Lord of Coucy, a French nobleman. The marriage contract was signed at Vincennes on 25 November 1338. The marriage produced one son, Enguerrand. The couple were married for eight years when in 1346, Enguerrand VI was killed in battle as part of the Hundred Years' War between France and England. Enguerrand was killed in one of a series of battles which ended with the Battle of Crécy on 26 August 1346. Their son Enguerrand succeeded his father as Lord of Coucy, and he later married Isabella, eldest daughter of King Edward III of England.