Duke of Northumberland

Duke of Northumberland is a title that has been created three times in English and British history, twice in the Peerage of England and once in the peerage of Great Britain.
1551 creation
The title was first created in the Peerage of England in 1551 for John Dudley, 1st Earl of Warwick. He had already been created Viscount Lisle in 1543 and Earl of Warwick in 1547, also in the Peerage of England. In 1553, Dudley advanced the claim of his daughter-in-law, Lady Jane Grey, to the English throne, but when she was deposed by Queen Mary I, Dudley was convicted of high treason and executed. An illegitimate son of one of his younger sons, Robert Dudley, 1st Earl of Leicester, Sir Robert Dudley, claimed the dukedom when in exile in Italy. On 9 March 1620 the Emperor Ferdinand II officially recognised the title, an act which infuriated James I of England.
1683 creation
George FitzRoy, 1st Earl of Northumberland, an illegitimate son of king Charles...