Henry Percy , 1st Earl of Northumberland Henry Percy , 1st Earl of Northumberland , 4th Baron Percy , titular King of Mann , KG , Lord Marshal ( 10 November 1341 – 20 February 1408 ) was the son of Henry de Percy , 3rd Baron Percy , and a descendent of Henry III of England . His mother was Mary of Lancaster , daughter of Henry , 3rd Earl of Lancaster , son of Edmund , Earl of Leicester and Lancaster , who was the son of Henry III . Henry Percy married Margaret Neville , daughter of Ralph Neville , 2nd Baron Neville de Raby , and Alice de Audley . They were the parents of Henry Percy , nicknamed " Harry Hotspur " . Life . Henry Percy was originally a follower of Edward III of England , for whom he held high offices in the administration of northern England . At a young age he was made Warden of the Marches towards Scotland in 1362 , with the authority to negotiate with the Scottish government . In February 1367 he was entrusted with the supervision of all castles and fortified places in the Scottish marches . He went on to support King Richard II and was created an Earl and briefly given the title of Marshal of England . After Richard elevated his rival Ralph Neville to the position of Earl of Westmorland in 1397 , Percy supported the rebellion of Henry Bolingbroke , who became King as Henry IV . On King Henry IV ' s coronation he was appointed Constable of England and granted the lordship of the Isle of Man . Percy and his son , Henry Percy , known as " Hotspur " , were given the task of subduing the rebellion of Owain Glyndŵr , but their attempts to make peace with the Welsh rebels did not meet with the king ' s approval . In 1403 the Percys turned against Henry IV in favour of Edmund Mortimer , 5th Earl of March , and then conspired with Owain Glyndŵr against King Henry . The Percy rebellion failed at the Battle of Shrewsbury , where Hotspur was killed . Since the earl did not directly participate in the rebellion , he was not convicted of treason . However , he lost his office as Constable . In 1405 Percy supported Richard le Scrope , Archbishop of York , in another rebellion , after which Percy fled to Scotland , and his estates were confiscated by the king . In 1408 Percy invaded England in rebellion once more and was killed at the Battle of Bramham Moor . Percy ' s severed head was subsequently put on display at London Bridge . In literature and media . Northumberland is a major character in Shakespeare ' s " Richard II " , " Henry IV , part 1 " , and " Henry IV , part 2 . " His position as a character in the Shakespearean canon inspired the character of Lord " Percy " Percy , " Duke " of Northumberland in the historical sitcom " The Black Adder " , set during the very late Plantagenet era . The novel " Lion of Alnwick " by Carol Wensby - Scott is the first volume of the Percy Saga trilogy which retells the story of " the wild and brilliant Percy family " and relates a fictionalised account of the 1st Earl of Northumberland and his son Henry " Hotspur " Percy ' s lives . The other novels in the trilogy , " Lion Dormant " and " Lion Invincible " tell the story of his other descendants and their role in the English War of the Roses . Henry Percy and his son Hotspur are also essential characters in Edith Pargeter ' s novel , " A Bloody Field by Shrewsbury " which recounts the events leading up to the Battle of Shrewsbury in 1403 . He is a major character in " My Lord John " by Georgette Heyer . Alnwick Castle , the traditional home of the Percy family , was featured in the Harry Potter movies as the location of Hogwarts .