He married Anne Neville, daughter of Sir Ralph Neville, 1st Earl of Westmoreland and Joan Beaufort, before 18 October 1424 (a dispensation having been issued as early as 7 August 1408, they being related in the 3rd degree of kindred on both sides). Their children are:
Catherine/Katherine (-26 Dec 1476), wife of Sir John Talbot, 3rd Earl of Shrewsbury
Sir Humphrey, Earl of Stafford (1428-)
Sir John (-8 May 1473, bur [Pleshey, Essex]), 9th Earl of Wiltshire, Chief Butler of England
Sir Henry (-4 Oct 1471)
Anne (-after 14 Apr 1472, bur Lingfield), wife of Sir Aubrey de Vere and of Sir Thomas, 5th Lord Cobham
Richard (-young) - see Notes
Joan/Jane (-after 31 Oct 1480), wife of Sir William, 2nd Viscount Beaumont, & of Sir William Knyvett
Elizabeth - see Notes
George (-young) - see Notes
William (-young) - see Notes
Margaret - see Notes
Sir Humphrey also had an illegitimate son and daughter (Anne, wife of William Rouse, Esq).
Sir Humphrey Stafford died on July 1460 at the battle of Northampton. He was buried at Grey Friars, Northampton. His will was proved on 2 December 1460.
"Buckingham appears as a fairly significant character in 2 Henry VI. He is a loyal Lancastrian supporter and fights for the Lancastrians at St Albans, where he is wounded. At the beginning of 3 Henry VI, the Yorkists report that Buckingham has been either wounded or killed during the battle. He is not mentioned again. In reality, Buckingham died in 1460, five years after the Battle of St Albans, at the Battle of Northampton. While Buckingham is not seen again, his grandson and heir is a major character in Richard III, who is ultimately executed by the tyrant king for turning on him."
Richardson names only 9 children, but MedLands lists 12, adding Richard, Margaret and Elizabeth. Richard is said to have died young (as also are Edward, George and William). There is no further information on Margaret and Elizabeth. A "primary source", namely a manuscript pedigree of ca. 1500, is cited for only the more significant children.
Wikipedia mentions Margaret.
George and William are said elsewhere to have been twins.
It may be possible to confirm family relationships with Humphrey by comparing test results with other carriers of his Y-chromosome or his mother's mitochondrial DNA.
Y-chromosome DNA test-takers in his direct paternal line on WikiTree: