The House of York was a cadet branch of the English royal House of Plantagenet that fought with the House of Lancaster, another cadet branch of the House of Plantagenet, for the English crown in the second half of the 15th century. The differences ultimately led to the Wars of the Roses. These wars are so named because both houses had roses in their coats of arms, the Yorks a white one and the Lancasters a red one.

Three of the members of the House of York became kings of England in the late 15th century: Edward IV, Edward V and Richard III. The House of York descended in the male line from Edmund of Langley, 1st Duke of York, the fourth surviving son of Edward III. In time, it also represented Edward III's senior line, when an heir of York married the heiress-descendant of Lionel, Duke of Clarence, Edward III's second surviving son. It is based on these descents that they claimed the English crown. Compared with its rival, the House of Lancaster, it had a superior claim to the throne of England according to cognatic primogeniture, but an inferior claim according to agnatic primogeniture. The reign of this dynasty ended with the death of Richard III of England at the Battle of Bosworth Field in 1485. It became extinct in the male line with the death of Edward Plantagenet, 17th Earl of Warwick, in 1499.

The fourth surviving legitimate son of Edward III and Philippa of Hainault, Edmund of Langley, 1st Duke of York, was created earl of Cambridge in 1362 and the first duke of York in 1385. Edmund's first marriage was to Isabella of Castile, Duchess of York, daughter of Peter of Castile and María de Padilla, and sister of Constance of Castile, second wife of Edmund's older brother John of Gaunt. Through this marriage Edmund had two sons, Edward, 2nd duke of York and the younger Richard of Conisburgh. His second marriage was to Joan Holland, whose sister Alianore Holland was mother to Anne Mortimer, the great-great-granddaughter of Edward III via Lionel of Antwerp, Duke of Clarence, second surviving son of Edward III, and the elder brother of John of Gaunt. Richard of Conisburgh married Anne Mortimer, the marriage producing two children, Isabel of Cambridge and Richard of York, 3rd Duke of York. It was through Anne Mortimer's lineage that the Yorkists derived their main claim to the throne.

Following Edmund of Langley's death in 1402, his son Edward succeeded to the dukedom but had no issue before he was killed at the Battle of Agincourt in 1415. His other son Richard had been executed for treason earlier in the same year following his involvement in the Southampton Plot to depose Henry V in favour of Edmund Mortimer, Richard's brother-in-law. The dukedom therefore passed to Richard's son, who became Richard of York, 3rd Duke of York. Being descended from Edward III in both the maternal and the paternal line gave Richard a significant claim to the throne if the Lancastrian line should fail, and by cognatic primogeniture arguably a superior claim. He emphasised the point by being the first to assume the Plantagenet surname in 1448. Having inherited the March and Ulster titles, he became the wealthiest and most powerful noble in England, second only to the king himself. Richard married Cecily Neville, a granddaughter of John of Gaunt, and had thirteen or possibly fifteen children:

Despite his elevated status, Richard Plantagenet was denied a position in government by the advisers of the weak Henry VI, particularly John Beaufort, 1st Duke of Somerset, and the queen consort, Margaret of Anjou. Although he served as protector of the realm during Henry VI's period of incapacity in 1453–54, his reforms were reversed by Somerset's party once the king had recovered.

The Wars of the Roses began the following year, with the First Battle of St Albans. Initially, Richard aimed only to purge his Lancastrian political opponents from positions of influence over the king. It was not until October 1460 that he claimed the throne for the House of York. In that year the Yorkists had captured the king at the battle of Northampton, but victory was short-lived. Richard and his second son Edmund were killed at the battle of Wakefield on 30 December.

Richard's claim to the throne was inherited by his son Edward. With the support of Richard Neville, 16th Earl of Warwick ("The Kingmaker"), Edward, already showing great promise as a leader of men, defeated the Lancastrians in a succession of battles. While Henry VI and Margaret of Anjou were campaigning in the north, Warwick gained control of the capital and had Edward declared king in London in 1461. Edward strengthened his claim with a decisive victory at the Battle of Towton in the same year, in the course of which the Lancastrian army was virtually wiped out.

The early reign of Edward IV was marred by Lancastrian plotting and uprisings in favour of Henry VI. Warwick himself changed sides, and supported Margaret of Anjou and the king's jealous brother George, Duke of Clarence, in briefly restoring Henry in 1470–71. However, Edward regained his throne, and the House of Lancaster was wiped out with the death of Henry VI himself, in the Tower of London in 1471. In 1478, the continued trouble caused by Clarence led to his execution in the Tower of London; popularly he is thought to have been drowned in a butt of malmsey wine.