John Clifford, 9th Baron Clifford (8 April 1435 – 28 March 1461) was a Lancastrian military leader during the Wars of the Roses. The Clifford family was one of the most prominent families among the northern English nobility of the fifteenth century; and by the marriages of his sisters John Clifford had links to some very important families of the time, including the earls of Devon. He was orphaned at about twenty years of age when his father was slain at the first battle of the Wars of the Roses, the Battle of St Albans in 1455. It was probably as a result of his father's death there that Clifford became one of the strongest supporters of Queen Margaret of Anjou, consort of King Henry VI, who ended up as effective leader of the Lancastrian faction.
Clifford had already achieved prominence in the north where, as an ally of the son of the earl of Northumberland, he took part in a feud against the Neville family, the Percy's natural rivals in Yorkshire. This consisted of a series of armed raids, assaults and skirmishes, and included an ambush on one of the younger Nevilles' wedding party in 1453. Historians have seen a direct connection between his involvement in the local feud in the north with the Nevilles, and his involvement in the national struggle against the duke of York, whom the Nevilles were closely allied with in the late 1450s. Although this was supposedly a period of temporary peace between the factions, Clifford and his allies appear to have made numerous attempts to ambush the Neville and Yorkist lords.
Armed conflict erupted again in 1459, and again Clifford was found on the side of the King and Queen. Clifford took part in the parliament that attainted the Yorkists – by now in exile – and he took a share of the profits from their lands, as well as being appointed to offices traditionally in their keeping. The Yorkist lords returned from exile in June 1460 and subsequently defeated a royal army at Northampton. As a result of the royalist defeat, Clifford was ordered to surrender such castles and offices as he had from the Nevilles back to them, although it is unlikely that he did so. In fact, he and his fellow northern Lancastrian lords merely commenced a campaign of destruction on Neville and Yorkist estates and tenantry, to such an extent that in December 1460, the duke of York and his close ally, the earl of Salisbury, raised an army and headed north to crush the Lancastrian rebellion. This winter campaign culminated in the Battle of Wakefield in the last days of the year, and was a decisive victory for the Lancastrian army, of which Clifford was by now an important commander. The battle resulted in the deaths of both York and Salisbury, but was probably most notorious for Clifford's slaying of Edmund, Earl of Rutland, York's seventeen-year old second son and the younger brother of the future King Edward IV. This may have resulted in Clifford's being nicknamed 'Butcher Clifford,' although historians disagree as to how widely used by contemporaries this term was.