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.
Sophia Palaiologina
The marriage between Sophia and Ivan III was proposed by Pope Paul II in 1469, probably with the hope of strengthening the influence of the Catholic Church in Russia, or the unification of the Orthodox and Catholic as was stipulated in the Council of Florence. Ivan III's motives for pursuing this union were probably connected with the status and rights of the Greek princess over Constantinople. The idea of this marriage perhaps was born in the mind of Cardinal Bessarion.