Henry had no further opportunities to reconquer his possessions in France after the collapse of his military campaign at the battle of Taillebourg. Henry's resources were quite inadequate in comparison to those of the French Crown, and by the end of the 1240s it was clear that King Louis had become the preeminent power across France. Henry instead adopted what historian Michael Clanchy has described as a "European strategy", attempting to regain his lands in France through diplomacy rather than force, building alliances with other states prepared to put military pressure on the French King. In particular, Henry cultivated Frederick II, hoping he would turn against Louis or allow his nobility to join Henry's campaigns. In the process, Henry's attention became increasingly focused on European politics and events rather than domestic affairs.