In 1241, he was at Poitiers, where his brother Alphonso, the new Count of Poitou, was to receive, in his presence, the homage of the neighboring lords whose suzerain he was.

A confidential letter arrived, addressed not to Louis himself, but to Queen Blanche, whom many faithful subjects continued to regard as the real regent of the kingdom, and who probably continued also to have her own private agents.

An inhabitant of Rochelle, at any rate, wrote to inform the queen-mother that a great plot was being hatched amongst certain powerful lords, of La Marche, Saintonge, Angoumois, and perhaps others, to decline doing homage to the new Count of Poitou, and thus to enter into rebellion against the king himself.

The news was true, and was given with circumstantial detail.
Hugh de Lusignan, Count of La Marche, and the most considerable amongst the vassals of the Count of Poitiers, was, if not the prime mover, at any rate the principal performer in the plot.

His wife, Joan (Isabel) of Angouleme, widow of the late King of England, John Lackland, and mother of the reigning king, Henry III., was indignant at the notion of becoming a vassal of a prince himself a vassal of the King of France, and so seeing herself--herself but lately a queen, and now a king's widow and a king's mother--degraded, in France, to a rank below that of the Countess of Poitiers.