What Philip had gained through victory in war, he sought to confirm by legal means. Philip, again acting as John's liege lord over his French lands, summoned him to appear before the Court of the Twelve Peers of France to answer for the murder of Arthur of Brittany. John requested safe conduct, but Philip only agreed to allow him to come in peace, while providing for his return only if it were allowed to after the judgment of his peers. Not willing to risk his life on such a guarantee, John refused to appear, so Philip summarily dispossessed the English of all lands. Pushed by his barons, John eventually launched an invasion of northern France in 1206. He disembarked with his army at La Rochelle during one of Philip's absences, but the campaign was a disaster. After backing out of a conference that he himself had demanded, John eventually bargained at Thouars for a two-year truce, the price of which was his agreement to the chief provisions of the judgment of the Court of Peers, including a loss of his patrimony.