Fortunately, William Marshall led the royal forces, defeating the rebel barons. John on his deathbed had asked William to become Henry's guardian. William Marshall was an obvious choice: he had been loyal to the crown for generations. Afterward, a regency government needed to be created to aid the young king. William asked Bishop of Winchester Peter des Roches to help guide Henry. He had been Henry's tutor since Henry was five.
The papal legate to England, Cardinal Guala Bicchieri, had declared the war against the barons to be a religious crusade, and threw his support to Henry, also making sure the ties between England and the papacy were strong. (Henry's father had declared England a papal fiefdom in order to gain the pope's total support.) Henry himself "took up the cross" and declared himself a crusader, giving him special protection from the pope.
Henry's authority as a king was somewhat restored through the efforts of William, Hubert de Burgh (mentioned here and here), and Peter des Roches, who was chosen to perform the coronation (seen here in a 13th century depiction). There were problems, however.: much of the civil structure across the country had collapsed during the war. The network of sheriffs who collected taxes had fallen apart.
Rebel barons (and even some loyalist ones) were ignoring the crown's demands for taxes, some building unapproved castles (the king had the right to approve castles, since they might be used in defense against him). These "adulterine" (unapproved) castles were a larger problem during The Anarchy.
Wales was always threatening rebellion. Henry finally resolved it by making the prince Llywelyn his justiciar (chief political officer) in Wales, underlining the crown's need to compromise over its ability to conquer.
Henry adopted Edward the Confessor as his patron saint. A few times that he planned to go on Crusade were foiled when he had to stay and deal with uprisings in his lands, especially those on the continent, such as Gascony.
His reign was long and troubled, and I'll talk about it more very soon, but first we have to focus on his most steadfast support, William Marshall, and the troubles after William died. See you tomorrow.