In 1214 King
John of England had assembled a formidable coalition against the
French. He landed in
Poitou while
Otto IV of Germany prepared to invade from the north. John chased off some French forces in the north of Poitou, and then moved to the southern edge of Brittany, opposite
Nantes. Peter drove him off after a brief skirmish but did nothing to hinder John's subsequent movement up the
Loire valley where he took a few Breton fortresses and then besieged
La Roche-aux-Moines. John's Poitevin vassals, however, refused to fight against a French force led by
Prince Louis of France. Meanwhile, Otto's army was crushed at
Bouvines, and the entire invasion foundered. It is not clear why John attempted to capture Nantes, even less why he would do so the hardest way, via the very well-defended bridge across the
Loire. Nor is it clear why Peter declined to harass his forces from the rear as John marched east. A likely explanation is that the two had come to some sort of agreement whereby John would leave Brittany alone for the moment, and in return the Bretons would not hinder him elsewhere. John had a prize he could dangle in front of Peter: the
Earldom of Richmond. This great
English honour had traditionally been held by the dukes of Brittany, and in fact a constant theme in Peter's political affairs was the desire to hold and retain the English revenues from
Richmond. Peter did not yield to King John's offers to accept the earldom and take up the king's side in his conflicts with the English barons, probably because he deemed John's prospects too uncertain. Moreover, Louis was again fighting against the English. But when Louis was defeated, Peter was sent as one of the negotiators for a peace treaty. After the negotiations were completed (in 1218),
William Marshal, the regent for the young
Henry III of England, recognized Peter as
Earl of Richmond, in place of Eleanor of Brittany who remained under English imprisonment. The center of the earldom's properties in
Yorkshire was in the hands of the Earl of Chester, whom the regent could not afford to antagonize, but Peter did receive the properties of the earldom outside of Yorkshire, which in fact generated the bulk of the earldom's income. In 1219 he participated in the capture of
Marmande and the siege of Toulouse during the
Albigensian Crusade. == Consolidation of power ==