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 maternal grandfather, Charles VI, shortly afterwards.
Henry inherited the Hundred Years' War (1337–1453), in which his uncle Charles VII contested his claim to the French throne. He is the only English monarch to have been also crowned King of France, in 1431. His early reign, when several people were ruling for him, saw the pinnacle of English power in France, but subsequent military, diplomatic, and economic problems had seriously endangered the English cause by the time Henry was declared fit to rule in 1437. He found his realm in a difficult position, faced with setbacks in France and divisions among the nobility at home.
Unlike his father, Henry is described as timid, shy, passive, well-intentioned and averse to warfare and violence; he was also at times mentally unstable. His ineffective reign saw the gradual loss of the English lands in France. Partially in the hope of achieving peace, in 1445 Henry married Charles VII's niece, the ambitious and strong-willed Margaret of Anjou. The peace policy failed, leading to the murder of one of Henry's key advisers, William de la Pole, 1st Duke of Suffolk, and the war recommenced, with France taking the upper hand; by 1453, Calais was Henry's only remaining territory on the continent.
As the situation in France worsened, there was a related increase in political instability in England. With Henry effectively unfit to rule, power was exercised by quarrelsome nobles, while factions and favourites encouraged the rise of disorder in the country. Regional magnates and soldiers returning from France formed and maintained increasing numbers of private armed retainers, with whom they fought one another, terrorised their neighbours, paralysed the courts, and dominated the government.