Thomas of Lancaster, 1st Duke of Clarence

Thomas of Lancaster, 1st Duke of Clarence, KG (1387 – 22 March 1421), also known as Thomas Plantagenet, was the second son of King Henry IV of England and his first wife, Mary de Bohun. He was born before 25 November 1387 as on that date his father's accounts note a payment made to a woman described as his nurse. Sandals and clothes were bought for him early in 1388, so the traditional birth date of 29 September 1388 may be safely discounted.

Marriage and issue
Thomas married Lady Margaret Holland, widow of John Beaufort, 1st Earl of Somerset and daughter of Thomas Holland, 2nd Earl of Kent in November or December of 1411. No children were born from this union, though Thomas was stepfather to her six children from her first marriage. He had, however, a natural son, Sir John Clarence, called "Bastard of Clarence" who fought by his father's side in France.

Life
During the wars of his elder brother Henry V in France, Clarence fought in the Siege of Rouen (July 1418 – 19 January 1419), where he commanded the besieging force; and in the Battle of Baugé on 22 March 1421. He was killed, by Sir Alexander Buchanan or Sir John de la Croise, during the latter. His natural son John accompanied the remains of his father from Baugé to Canterbury for their interment. This Sir John Clarence had a grant of lands in Ireland from Henry V and was buried in Canterbury Cathedral. The noble de Langlée family of France claimed him for their ultimate ancestor.

His executors, as seen in a legal record of 1430, were John Colvylle, of Neuton, Cambs, knight; Henry Merston, of Westminster, clerk & his widow, Margaret, Duchess of Clarence, living in Bermondsey, Surrey.

Titles and styles

 * Duke of Clarence (9 July 1412–22 March 1421); extinct upon his death until the Third Creation of it in (1461)
 * 1st Earl of Aumale (9 July 1412–22 March 1421); extinct upon his death

Honours

 * Knight of the Bath (12 October 1399–22 March 1421)
 * Knight, Order of the Garter (1400–22 March 1421)

Offices held

 * Lord High Steward of England (1399–1421) &mdash; he was the last permanent holder of this office, the highest in medieval England.
 * Chief Governor of Ireland (1401–1413)
 * Lord High Admiral (1405–1406)
 * Lieutenant of Aquitaine (1412–1413)
 * Lord High Steward of Chester (1415)
 * Constable of the Army (1417)
 * Lieutenant-General of the Army in France and Normandy (1417 and 1421)

Arms
Sources conflict as to Thomas' arms — as a son of the sovereign, Thomas bore the arms of the kingdom, differenced by either:
 * a label of three points ermine.
 * a label of three points ermine, each cantoned gules, as depicted in the above image.