Career
According to Hall"s Chronicle, Knyvett was a frequent participant in the jousts and pageants of the new king"s glittering court and was made Henry"s Master of the Horse in 1510. When Henry declared war on France in 1512, Knyvett, along with Sir John Carew, was given command of the royal flagship, the Regent. With a number of court favourites commanding other vessels, a small fleet set sail for the coast of Brittany.
On 10 August 1512 they engaged a slightly larger French fleet, and a violent melee known as the Battle of Saint Mathieu ensued off the coast of Brest.
Knyvett"s ship grappled with the Breton command vessel Cordelière, and was engaged in boarding her when the Cordelière"s powder magazine blew up (some say it was deliberately ignited). The two vessels burst into flame.
Knyvett and Carew both perished, along with the Breton captain Hervé de Portzmoguer and more than 1,700 men, both French and English. Knyvett married, before 9 July 1506, Muriel Howard, the widow of John Grey, 2nd Viscount Lisle, by whom she was the mother of Elizabeth Grey, Viscountess Lisle, who was at one time betrothed to Charles Brandon, 1st Duke of Suffolk.
Four months after her husband"s death, Muriel Howard died in childbirth between 13 and 21 December 1512.
The actress and theatre director Sally Knyvette, who starred as Jenna Stannis in the British science fiction television series Blake"s 7, is a direct descendant of Sir Thomas Knyvet. On the television series The Tudors, a fictionalized Sir Anthony Knivert is based on Knyvett and played by Callum Blue.