Henry Percy (1342 - 1408), 1st earl of Northumberland, was the son of Henry, 3rd baron Percy, and the father of Henry " Harry Hotspur" Percy. His mother was Mary of Lancaster, daughter of Henry, 3rd Earl of Lancaster, son Edmund Crouchback, 1st Earl of Lancaster[?], son of Henry III of England.
Originally a follower of Edward III of England, for whom he held high offices in the administration of northern England, Henry Percy went on to support King Richard II. He was given the title of Marshal of England and created an earl at Richard's coronation (1377), but he switched to the side of Henry Bolingbroke (later, Henry IV) after Richard created his chief rival, Ralph Neville[?], 1st earl of Westmorland in 1399. On Henry's coronation he was appointed Constable of England and granted the lordship of the Isle of Man. In 1403 Percy turned against Henry IV in favor of Edmund Mortimer, 5th earl of March, and then conspired with Owen Glendower against King Henry. This rebellion failed at the Battle of Shrewsbury but, since Percy did not directly participate, he lost his office as Constable but was not convicted of treason. But in 1405 Percy supported Richard le Scrope, archbishop of York, in another rebellion, and then Percy fled to Scotland, and his estates were confiscated by the king. In 1408 Percy invaded England and was killed at the Battle of Branham Moor[?].
With his father he helped depose Richard II of England, but later with his uncle Thomas Percy, Earl of Worcester he led a rebellion against King Henry IV in 1403, forming an alliance with another rebel, Owen Glendower. Before they could join forces, Hotspur was defeated and killed at the Battle of Shrewsbury. He is a major character in Shakespeare's Henry IV, Part 1[?].
Henry Percy (1392/3 - 1455), 1st Earl of Northumberland, was the son of Henry 'Hotspur' Percy. He was restored to favor by Henry V, receiving his grandfather's estates and and re-creation of the earldom. Percy was on the regency council in the early years of the reign of Henry VI. He was killed fighting on the Lancastrian side at the Battle of St Albans. Percy married Eleanor Neville, daughter of Ralph, 1st Earl of Westmorland, and was suceeded as earl by his eldest son.
Henry Percy (1421 - 1461), 2nd Earl of Northumberland, was the son of the 1st earl (of the second creation). He fought on the Lancastrian side at the Battle of Wakefield, and commanded the Lancastrian van at the Battle of Towton, where he was killed.
Henry Percy (1449 - 1489), 3rd Earl of Northumberland, son of the 3rd earl, was the only one of the family to appear to take the Yorkist side. His father's earldom was forfeited at the Battle of Towton by the victorious Yorkists, and Percy was imprisoned. After swearing fealty to Edward IV he was released (1469). The earldom was restored in 1473, and Percy held many of the important government posts in the north of England which were traditional in his family. He commanded the Yorkist reserve at the Battle of Bosworth Field, but never committed his forces to the battle, which played an important part in Richard III's defeat.
Percy was again imprisoned by the new king, Henry VII, but was soon released and returned to his old posts. He was killed 28 April 1489 by a mob enraged by his efforts to collect some new and higher taxes.
Henry Percy (1500 - 1537), 6th earl of Northumberland (in 1527).
Lord Henry became betrothed to Anne Boleyn, the future second queen of Henry VIII probably in the spring of 1523, when Lord Percy was page to Cardinal Wolsey. On hearing the news, Lord Henry was scolded before his servants by the Cardinal, since permission for the marriage had not been sought from his father nor the king, who also had an interest due to the importance of the Northumberland earldom. His father refused permission for the marriage, and he later went on to marry Lady Mary Talbot, an unhappy marriage without issue. After spending his inheritance lavishly and transferring various estates to friends, the remainder of his estates went to the crown on his death. He was also a member of the jury that convicted Queen Anne of adultery.