18: The Duke of Sussex@Hanover

The Duke of Sussex is a substantive title, one of several royal dukedoms in the United Kingdom. As used at the English and British courts, it takes its name from the county of Sussex in England.
The dukedom was first conferred on 24 November 1801 upon Prince Augustus Frederick,^[2] the sixth son of King George III. He was made Baron Arklow and Earl of Inverness, at the same time, also in the Peerage of the United Kingdom. The title became extinct upon Prince Augustus Frederick's death in 1843, as although he had surviving male issue, his marriage to his sons' mother, Lady Augusta Murray, had been annulled for lack of royal permission under the Royal Marriages Act 1772, rendering the sons illegitimate and unable to inherit the ducal title.

The title was next granted to Prince Harry on the morning of his wedding to Meghan Markle, 19 May 2018. Prince Harry was granted the subsidiary titles Earl of Dumbarton and Baron Kilkeel at the same time.

Prince Augustus Frederick, Duke of Sussex, KG, KT, GCB, GCH, PRS, FRSA (27 January 1773 – 21 April 1843) was the sixth son and ninth child of King George III and his consort Charlotte of Mecklenburg-Strelitz. He was the only surviving son of George III who did not pursue an army or navy career. 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.^[1]

The House of Hanover (or the Hanoverians /ˌhænəˈvɪəriənz, -noʊ-, -ˈvɛr-/;^[1]^[2] German: Haus Hannover) is a German royal dynasty that ruled the Electorate and then the Kingdom of Hanover, and then also provided monarchs of Great Britain and Ireland from 1714 to 1800 and ruled the United Kingdom of Great Britain and Ireland from its creation in 1801 until the death of Queen Victoria in 1901. Upon Victoria's death, the British throne passed to her eldest son Edward VII, a member of the House of Saxe-Coburg and Gotha through his father.
The House of Hanover was formally named the House of Brunswick-Lüneburg, Hanover line, as it was originally a cadet branch of the House of Brunswick-Lüneburg. The senior branch became extinct in 1884, and the House of Hanover is now the only surviving branch of the House of Welf, which is the senior branch of the House of Este. The current head of the House of Hanover is Ernest Augustus, Prince of Hanover.