Augustus Frederick was the sixth son of George III and his queen, Sophia Charlotte, daughter of Charles I Duke of Mecklenburg Strelitz. Unable to follow a career in the army or navy because of poor health, he studied at the University of Göttingen, travelled on the Continent and wished to take holy orders. On the 4 April 1793 he married Lady Augusta Murray, second daughter of John 4th Earl of Drumore, secretly at Rome and the marriage was repeated, again secretly, at St George's Hanover Square later in the year. After the birth of a son in 1794, the marriage came to the notice of George III, who in accordance with the provisions of the Royal Marriage Act of 1777, declared it void. For some years the couple ignored this annulment. It was not until 7 November 1801 that Augustus Frederick was raised to the peerage as Duke of Sussex, Earl of Inverness,and Baron Arklow. This was perhaps because of his liberal opinions in politics which displeased his father. Lady Augusta died in 1830, and he went through a form of marriage, about 2 May 1831, with Lady Cecilia Laetitia Buggin, afterwards Underwood, eldest daughter of Arthur Saunders, 2nd Earl of Arran, and widow of Sir George Buggin. She was created Duchess of Inverness in 1840. The Duke was an ardent book collector and formed a large library, with the help of his Surgeon and Librarian, Thomas Joseph Pettigrew. He had a special interest in theology and Biblical texts, of which he owned more than 1,000 editions. Pettigrew compiled a catalogue of the collection of which the first volume covering the Bibles was published in two parts, in 1827 and 1839. The Duke hoped that his collection would be bought for the nation after his death. It was valued at £15,081 by Evans the auctioneers, but the British Museum was not interested, and it was sold at auction by Evans in six parts between July 1844 and August 1845.