Thomas of Lancaster, Duke of Clarence

Thomas of Lancaster
Duke of Clarence
Drawing of his tomb effigy
Born	Autumn 1387[1] Probably London
Died	22 March 1421 (aged 33) Battle of Baugé, Anjou, France
Burial	Canterbury Cathedral, Kent
Spouse	Margaret Holland (m. 1411)
Issue	John of Clarence (illegitimate)
House	Lancaster
Father	Henry IV of England
Mother	Mary de Bohun

Thomas of Lancaster, Duke of Clarence (c. autumn 1387 – 22 March 1421) was a medieval English prince and soldier, the second son of Henry IV of England, brother of Henry V, and heir to the throne in the event of his brother's death. He acted as counselor and aide to both.

His father appointed him Lord Lieutenant of Ireland in 1401. Thomas, who was only fourteen, landed in Dublin in November 1401, and spent much of the next eight years in Ireland. He was nearly killed in a skirmish near Dublin in 1406.^[2]

After his father's death, he participated in his brother's military campaigns in France during the Hundred Years' War. Left in charge of English forces in France when Henry returned temporarily to England after his marriage to Catherine of Valois, Thomas led the English in their disastrous defeat at the hands of a mainly Scottish force that came to the aid of the French at the Battle of Baugé. In a rash attack, he and his leading knights were surrounded, and Thomas was killed at age 33.