Louis I, Grand Duke of Hesse
In 1776, he became engaged to Sophie Dorothea of Württemberg, eldest daughter of Frederick II Eugene, Duke of Württemberg. The engagement was broken off so that Sophia Dorothea could marry Louis's recently widowed brother-in-law Tsarevich Paul Petrovich, son and heir of Catherine II "the Great", Empress of Russia. He received a monetary compensation when the engagement was broken.
Duke George of Oldenburg
On 3 August 1809, George married Grand Duchess Catherine Pavlovna of Russia, the fourth daughter of Paul I of Russia and Sophie Dorothea of Württemberg and favorite sister of the Emperor Alexander I of Russia. The events behind their marriage began when Napoleon Bonaparte, hoping to secure a Russian alliance as well as a male heir, hinted his desire to marry Catherine after finalizing his divorce with Empress Joséphine. This so horrified the Russian imperial family that Catherine's mother immediately arranged her marriage to her cousin, Duke George. The day the marriage occurred, Duke George received the style "Imperial Highness" and was appointed the governor-general of the three central provinces of Tver, Yaroslavl and Novgorod.