" Henry III (1 October 1207 – 16 November 1272), also known as Henry of Winchester, was King of England, Lord of Ireland, and Duke of Aquitaine from 1216 until his death in 1272.[1] The son of King John and Isabella of Angoulême, Henry assumed the throne when he was only nine in the middle of the First Barons' War. Cardinal Guala Bicchieri declared the war against the rebel barons to be a religious crusade and Henry's forces, led by William Marshal, defeated the rebels at the battles of Lincoln and Sandwich in 1217. Henry promised to abide by the Great Charter of 1225, a later version of the 1215 Magna Carta, which limited royal power and protected the rights of the major barons. His early rule was dominated first by Hubert de Burgh and then Peter des Roches, who re-established royal authority after the war. In 1230, the King attempted to reconquer the provinces of France that had once belonged to his father, but the invasion was a debacle. A revolt led by William Marshal's son Richard broke out in 1232, ending in a peace settlement negotiated by the Church. "

On 11 November 1216 at Gloucester, upon the death of King John, William Marshal was named by the king's council (the chief barons who had remained loyal to King John in the First Barons' War) to serve as protector of the nine-year-old King Henry III, and regent of the kingdom. In spite of his advanced age (around 70) he prosecuted the war against Prince Louis and the rebel barons with remarkable energy. In the battle of Lincoln he charged and fought at the head of the young King's army, leading them to victory. He was preparing to besiege Louis in London when the war was terminated by the naval victory of Hubert de Burgh in the straits of Dover.