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.
William I of Württemberg
"Russia": Another paternal aunt of William's, Sophie, married the future Paul I of Russia and took the name Maria Feodorovna. This family tie to Russia had important political consequences for the later Kingdom of Württemberg since the reorganisation of Europe in the wake of the Congress of Vienna. William's second wife, Catherine Pavlovna, was his first cousin as the daughter of Paul and Maria Feodorovna. After Catherine died in 1819, the family relationship with Russia was renewed with the wedding of William's eldest son, Charles, to Grand Duchess Olga Nikolaevna. Olga was the granddaughter of Maria Feodorovna and the niece of William's second wife, Catherine. Her father was Nicholas I and her mother was Alexandra Feodorovna, the sister of the Prussian kings Frederick William IV and William I, later the German Emperor.