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 Dorothea of Hanover
When the crown prince was liberated after the wedding of his sister, Sophia Dorothea resumed negotiations with Great Britain to marry him to Princess Amelia, and her next daughter, Philippine Charlotte, to the Prince of Wales, thus still completing her life project of an Prussian-British marriage alliance. These plans was crushed in 1733, when Frederick William instead announced a marriage alliance with Brunswick by marrying crown prince Frederick to Elisabeth Christine of Brunswick-Wolfenbüttel-Bevern and Philippine Charlotte to Duke Charles I of Brunswick-Wolfenbüttel.
She then continued her life ambition of a Prussian-British marriage alliance, accomplishing a "reconciliation between the houses of England and Prussia negotiated by the Queen", this time between the Prince of Wales and her daughter Louisa Ulrika: