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.
Duke Peter of Oldenburg
On 23 April 1837 Duke Peter married Therese Wilhelmine Friederikke, Princess of Nassau-Weilburg in Biebrich. This was a happy marriage that lasted for more than thirty years. They had eight children, three of them died early. A daughter Cecilie died in childhood in 1843 and another daughter, Catherine and a son George died from tuberculosis in 1866 and 1871 respectively. Duke Peter and his wife led an exemplary family life, and looked carefully after the education of their children. The family spent the winter months in Peterhof and moved for the summer to their other residence Kamenoi-Ostroff.