Henry VI (6 December 1421 – 21 May 1471) was King of England from 1422 to 1461 and again from 1470 to 1471, and disputed King of France from 1422 to 1453. The only child of Henry V, he succeeded to the English throne at the age of nine months upon his father's death, and succeeded to the French throne on the death of his grandfather Charles VI shortly afterwards. Henry inherited a long-running conflict in France, known as the Hundred Years' War, where Charles VII contested his claim to the French throne. Henry married Charles' niece, Margaret of Anjou, partially in the hope of achieving peace in 1445, but the policy failed, leading to the murder of William de la Pole, one of Henry's key advisors. The war recommenced, with France taking the upper hand; by 1453, Calais was Henry's only remaining territory on the continent.