Ernest Augustus, King of Hanover

Ernest Augustus was King of Hanover from 20 June 1837 until his death in 1851. As the fifth son of George III of the United Kingdom and Hanover, he initially seemed unlikely to become a monarch, but none of his older brothers had a legitimate son. When his brother William IV, who ruled both kingdoms, died in 1837, his niece Victoria inherited the British throne under British succession law, while Ernest succeeded in Hanover under Salic law, which barred women from the succession. This ended the personal union between Britain and Hanover that had begun in 1714. During Victoria's reign, he was heir presumptive to the British throne until the birth of his great-niece Victoria, Princess Royal, in 1840.