The House of York, a branch of the Plantagenet family produced 3 Kings of England- Edward IV, the boy king Edward V and Richard III. They descended in the male line from Edmund of Langley, 1st Duke of York, who was the fourth surviving son of Edward III, but were also descended in the senior line from Edward being cognatic descendants (through the female line) of Lionel, Duke of Clarence, Edward's second surviving son. The Yorkist claimants, therefore, held a senior claim to their Lancastrian rivals according to cognatic primogeniture but a junior claim according to agnatic primogeniture.
Edmund of Langley, 1st Duke of York (1341 - 1402), the founder of the House of York, was the fourth surviving son of Edward III. He had two sons Edward, Duke of York, who died at Agincourt and Richard, Earl of Cambridge. The Yorkist dynasty based their claim to the throne through the marriage of his younger son, Richard, to Anne Mortimer, great-granddaughter of Lionel of Antwerp, the second son of Edward III. Richard, Earl of Cambridge was executed by the Lancastrian king Henry V for his involvement in a plot to depose the Lancastrian King Henry V in favour of his brother-in-law, Edmund, Earl of March, the appointed heir of Richard II. When Edmund later died his claim to the throne devolved on his sister Anne Mortimer. The dukedom of York and the Mortimer claim to the throne passed to her son, Richard Plantagenet.
Richard Plantagenet, Duke of York produced four surviving sons, Edward, Earl of March (1442-1483), who succeeded to the throne as King Edward IV in 1461. Edmund of Langley, Earl of Rutland (b.1443), was killed at the Battle of Wakefield along with his father in 1460. George Duke of Clarence, Shakespeare's, 'false, fleeting, perjured Clarence', who was famously drowned in a butt of malmsey in the Tower of London in 1478 and Richard, Duke of Gloucester (1452-1485). Edward IV left the crown to his young son, Edward V, the elder of the so-called 'Princes in the Tower', but the throne was usurped by his uncle, Richard Duke of Gloucester, who ascended the throne as Richard III (1452-1485). The young Edward V and his brother, Richard, Duke of York, disappeared into the depths of the Tower of London and were never seen alive again. Richard III was killed in battle at Bosworth Field in 1485. The new king, Henry VII, who represented the Lancastrian line, married Edward IV's eldest daughter Elizabeth of York, thereby uniting the claims of both houses in the person of their son, King Henry VIII.
B. 1470 Son of-Edward IV & Elizabeth Woodville R. 1483
B. 1452 Son of-Richard Duke of York & Cecily Neville R. 1483-85