Alys at Messina in 1191. Some of Alys's dowry that had been given over to Richard during their engagement was part of the territory of Vexin. This should have reverted to Philip upon the end of the betrothal, but Philip, to prevent the collapse of the Crusade, agreed that this territory was to remain in Richard's hands and would be inherited by his male descendants. Should Richard die without an heir, the territory would return to Philip, and if Philip died without an heir, those lands would be considered a part of Normandy. Returning to France in late 1191, Philip began plotting to find a way to have those territories restored to him. He was in a difficult situation, as he had taken an oath not to attack Richard's lands while he was away on a crusade. The Third Crusade ordained territory under the protection of the Church in any event. Philip was unsuccessful in requesting a release from his oath from Pope Celestine III, so he was forced to build his own casus belli. On 20 January 1192, Philip met with William FitzRalph, Richard's seneschal for Normandy. Presenting some documents purporting to be from Richard, Philip claimed that the English king had agreed at Messina to hand disputed lands over to France. Not having heard anything directly from their sovereign, FitzRalph and the Norman barons rejected Philip's claim to Vexin. Philip at this time also began spreading rumors about Richard's action in the east to discredit the English king in the eyes of his subjects. Among the stories Philip invented included Richard being involved in treacherous communication with Saladin, alleging he had conspired to cause the fall of Gaza, Jaffa, and Ashkelon, and that he had participated in the murder of Conrad of Montferrat. Finally, Philip made contact with John, Richard's brother, whom he convinced to join the conspiracy to overthrow the legitimate king of England. At the start of 1193, John visited Philip in Paris, where he paid homage for Richard's continental lands. When word reached Philip that Richard had finished crusading and had been captured on his way back from the Holy Land, he promptly invaded Vexin. His first target was the fortress of Gisors, commanded by Gilbert de Vascoeuil, which surrendered without putting up a struggle. Philip then penetrated deep into Normandy, reaching as far as Dieppe. To keep the duplicitous John on his side, Philip