Dacre was the third son of Thomas Dacre, 6th Baron Dacre (1387–1457/1458), by his wife Lady Philippa Neville (1386–1453), the daughter of Ralph Neville, 1st Earl of Westmorland. He was born at Naworth Castle, Cumberland, about 1424, one of at least nine children born to his parents between 1410 and 1426. He married Mabel Parr, a daughter of Sir Thomas Parr of Kendal, by his marriage to Alice Tunstall, a daughter of Sir Thomas Tunstall, of Thurland Castle.
He was later pardoned, regained the family estates, was summoned to parliament as a baron, attended the coronation of Richard III, and was appointed Governor of Carlisle and Warden of the West Marches.
He remained loyal to the House of Lancaster when Henry VI was deposed by Edward IV and fought on the Lancastrian side at the Battle of Towton of 1461, after which he was attainted. Dacre"s elder brother, Ralph, was summoned to parliament by Henry VI as Baron Dacre in 1459. The brothers remained on the side of the House of Lancaster when Henry VI was deposed by Edward IV of the House of York, and both fought for Lancaster at the Battle of Towton of 1461.
On 8 April 1473 King Edward IV confirmed Dacre as heir male of his father, but allowed the Barony of Dacre to pass to the heir general.
By letters patent he created Dacre Baron Dacre of Gilsland, declaring "that the said Humfrey Dacre, Knight, and the heirs male of the body of the said Thomas, late Lord Dacre, comyng, bee reputed, had, named and called the Lord Dacre of Gillesland". Dacre was summoned to the House of Lords between 15 November 1482 and 9 December 1483, the writs of summons being addressed to Humfrido Dacre de Gillesland.
On 6 July 1483, he attended the coronation of Richard III. He was Governor of Carlisle Castle and Warden of the West Marches from 1484. Dacre"s widow Mabel, Lady Dacre, died on 14 November 1508 and was buried with her husband"s remains at Lanercost Priory, Cumberland.
