Henry FitzRoy, 1st Duke of Grafton

Henry FitzRoy, 1st Duke of Grafton KG (28 September 1663 – 9 October 1690) was the illegitimate son of King Charles II of England by Barbara Villiers, Countess of Castlemaine.

On 1 August 1672 he was married at the age of nine to the five-year-old Isabella, the daughter and heiress of Henry Bennet, 1st Earl of Arlington. The wedding ceremony was repeated on 7 November 1679. They were parents to Charles FitzRoy, 2nd Duke of Grafton. Diana, Princess of Wales, was one of his descendants.

At the time of his marriage, Henry was created Baron Sudbury, Viscount Ipswich, and Earl of Euston; in 1675 he was created Duke of Grafton. Charles II made him a Knight of the Garter in 1680. He was made a colonel of the Grenadier Guards in 1681.

He was brought up as a sailor, and saw military service at the siege of Luxembourg in 1684. In that year, he received a warrant to supersede Sir Robert Holmes as Governor of the Isle of Wight, when the latter was charged with making false musters. However, Holmes was acquitted by court-martial and retained the governorship. In 1686 he killed John Talbot, brother of the Earl of Shrewsbury, in a duel.

At King James II's coronation Grafton was Lord High Constable. During the rebellion of the Duke of Monmouth he commanded the royal troops in Somerset; but later he acted with John Churchill, and joined William of Orange to overthrow the King in the Revolution of 1688.

He died in 1690 of a wound received at the storming of Cork while leading William's forces. He was 27. In October 1697 his widow married Sir Thomas Hanmer, a young Buckinghamshire baronet.

Legacy
The Duke of Grafton owned land in what was then the countryside near Dublin, Ireland, which later became part of the city. A country lane on this land eventually developed into Grafton Street, one of Dublin's main streets.

He is an ancestor of the Earls Spencer of Althorp, Diana, Princess of Wales, and also Diana's sons, Prince William, Duke of Cambridge, and his younger brother, Prince Harry.