Short answers, pulled from the story.
Henry FitzRoy, Duke of Richmond and Somerset, was the illegitimate son of Henry VIII of England and his mistress Elizabeth Blount, born around the 15th of June 1519. He was the only child born out of wedlock whom Henry VIII ever publicly acknowledged. He died on the 23rd of July 1536 at St. James's Palace, aged seventeen.
Elizabeth Blount was a lady-in-waiting to Catherine of Aragon and the mistress of Henry VIII. She gave birth to FitzRoy at the Augustinian priory of St Laurence at Blackmore, near Ingatestone in Essex, and later married Gilbert Tailboys, 1st Baron Tailboys of Kyme.
Henry FitzRoy was created Duke of Richmond, Duke of Somerset, and Earl of Nottingham in a ceremony at Bridewell Palace on the 18th of June 1525, and was elected a Knight of the Garter that same month. He was also appointed Lord High Admiral of England, Lord President of the Council of the North, Warden of the Marches towards Scotland, and Governor of Carlisle, giving him nominal authority over the whole of northern England at the age of six.
Henry VIII elevated FitzRoy at Bridewell Palace because he lacked a legitimate male heir with Catherine of Aragon. By 1525 his only surviving legitimate child was nine-year-old Princess Mary, and FitzRoy was the only son Henry had publicly acknowledged. The double dukedom he received was unprecedented for an illegitimate child.
The Second Succession Act, being drafted in 1536, would have permitted Henry VIII to designate Henry FitzRoy his heir, but there is no evidence the king intended to do so. The Imperial ambassador Eustace Chapuys reported on the 8th of July 1536 that FitzRoy was consumptive and incurable. He died on the 23rd of July 1536, before any formal designation was made.
Henry FitzRoy is buried at the Church of St Michael the Archangel in Framlingham, Suffolk. He was first interred at Thetford Priory in Norfolk, the mausoleum of the Howard family, but when the priory faced dissolution in 1540, Thomas Howard moved his remains to Framlingham. His tomb bears the motto of the Order of the Garter, "Honi soit qui mal y pense," and carved Old Testament scenes around its sides.