The Royal Marriages Act 1772 was an Act of the Parliament of Great Britain which prescribed the conditions under which members of the British royal family could contract a valid marriage, in order to guard against marriages that could diminish the status of the royal house. The right of veto vested in the sovereign by this Act provoked severe adverse criticism at the time of its passage.

Prince Augustus Frederick, Duke of Sussex, was the sixth son and ninth child of King George III and his queen consort, Charlotte of Mecklenburg-Strelitz. He was the only surviving son of George III who did not pursue an army or navy career. A Whig, he was known for his liberal views, which included reform of Parliament, abolition of the slave trade, Catholic Emancipation, and the removal of existing civil restrictions on Jews and Dissenters.