From the longer Wikipedia page 
Thomas Clifford, 8th Baron de Clifford, also 8th Lord of Skipton (25 March 1414 – 22 May 1455), was the elder son of John, 7th Baron de Clifford, and Elizabeth Percy, daughter of Sir Henry Percy.
Clifford inherited the barony and the title of High Sheriff of Westmorland at the age of seven upon his father's death at the Siege of Meaux (Wikipedia page ) on 13 March 1422. He made proof of age in 1435/6.
In 1435 Clifford campaigned with John of Lancaster, 1st Duke of Bedford in France, and about 1439 led the English forces which defended Pontoise against Charles VII of France. In 1450/51 he was sent as an embassy for King James III of Scotland.
Clifford was slain fighting on the Lancastrian side at the First Battle of St Albans on 22 May 1455, the first battle in the Wars of the Roses, and was buried at St Alban's Abbey. He was succeeded by his elder son, John, 9th Baron de Clifford.