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.
John Jones Maesygarnedd
In 1656 Jones married again. His second wife was Catherine Whitstone (baptised on 7 February 1597), the third sister of Oliver Cromwell, and the widow of Roger Whitstone, a Parliamentary army officer who had campaigned in the Low Countries, she had three sons and two daughters. Catherine received an annual settlement of £300 from the estate of her former husband to which Oliver Cromwell added an annuity of £150. She and Jones had no children. Her husband opposed Richard Cromwell when he was Protector, and Richard stopped her annuity. From a letter of Catherine's that was published in the 19th century, it seems that she had Royalist sympathies as she disproved of the execution of Charles I.