Apparently yielding to the counsels of the Earl, he despatched him in 1467 to treat for peace with Lewis at Rouen.
Warwick was received with honours which marked the importance of his mission in the French king's eyes.

Bishops and clergy went out to meet him, his attendants received gifts of velvet robes and the rich stuffs of Rouen, and for twelve days the Earl and Lewis were seen busy in secret conference.

But while the Earl was busy with the French king the Great Bastard of Burgundy crossed to England, and a sumptuous tourney, in which he figured with one of the Woodvilles, hardly veiled the progress of counter-negotiations between Charles and Edward himself.

The young king seized on the honours paid to Warwick as the pretext for an outburst of jealousy.

The seals were suddenly taken from his brother, the Archbishop of York, and when the Earl himself returned with a draft-treaty, stipulating a pension from France and a reference of the English claims on Normandy and Guienne to the Pope's decision, Edward listened coldly and disavowed his envoy.
[Sidenote: The overthrow of Warwick] Bitter reproaches on his intrigues with the French king marked even more vividly the close of Warwick's power.