Maria Feodorovna (Sophie Dorothea of Württemberg)
Sophie Dorothea arrived in St Petersburg that September, converted to the Russian Orthodox Church, and took the name Maria Feodorovna. She married Paul on 26 September 1776. In spite of her husband's difficult character, Maria Feodorovna made a success of her marriage. During the long reign of her mother-in-law, the Russian Empress, Catherine II, Maria and Paul were completely excluded from any political influence, as mother and son mistrusted each other. Maria Feodorovna sided with her husband and lost the initial affection Catherine II had for her. Paul and Maria were forced to live in isolation at Gatchina, but they were devoted to each other and had ten children including: Tsar Alexander I, Tsar Nicholas I of Russia, Grand Duchess Maria of Saxe-Weimar-Eisenach, Queen Catherine of Wurttemberg and Queen Anna Pavlovna of the Netherlands.
Morganatic marriage
Perhaps the most famous example in modern times was the 1900 marriage of the heir to the throne of Austria-Hungary, Archduke Franz Ferdinand, and Bohemian aristocrat Countess Sophie Chotek von Chotkowa. The marriage was initially resisted by Emperor Franz Joseph I, but after pressure from family members and other European rulers, he relented in 1899 (but did not attend the wedding himself). The bride was made Princess (later Duchess) of Hohenberg, their children took their mother's new name and rank, but were excluded from the imperial succession. The Sarajevo assassination in 1914, killing both the Archduke Franz Ferdinand and his wife Sophie, triggered the First World War.