This time the King declared that the charters were issued of his own "spontaneous and free will" and confirmed them with the royal seal, giving the new Great Charter and the Charter of the Forest of 1225 much more authority than any previous versions. The barons anticipated that the King would act in accordance with these definitive charters, subject to the law and moderated by the advice of the nobility. Early rule (1227–34) Invasion of France Henry assumed formal control of his government in January 1227, although some contemporaries argued that he was legally still a minor until his 21st birthday the following year. The King richly rewarded Hubert de Burgh for his service during his minority years, making him the Earl of Kent and giving him extensive lands across England and Wales. Despite coming of age, Henry remained heavily influenced by his advisers for the first few years of his rule and retained Hubert as his justiciar to run the government, granting him the position for life. The fate of Henry's family lands in France still remained uncertain. Reclaiming these lands was extremely important to Henry, who used terms such as "reclaiming his inheritance", "restoring his rights" and "defending his legal claims" to the territories in diplomatic correspondence. The French kings had an increasing financial, and thus military, advantage over Henry. Even under John, the French Crown had enjoyed a considerable, although not overwhelming, advantage in resources, but since then, the balance had shifted further, with the ordinary annual income of the French kings almost doubling between 1204 and 1221. Louis VIII died in 1226, leaving his 12-year-old son, Louis IX, to inherit the throne, supported by a regency government. The young French king was in a much weaker position than his father, and faced opposition from many of the French nobility who still maintained their ties to England, leading to a sequence of revolts across the country. Against this background, in late 1228 a group of potential Norman and Angevin rebels called upon Henry to invade and reclaim his inheritance, and Peter I, Duke of Brittany, openly revolted against Louis and gave his homage to Henry. Henry's preparations for an invasion progressed slowly, and when he finally arrived in Brittany with an army in May 1230, the campaign did not go well. Possibly on the advice of Hubert, the King decided to avoid battle with the French by