Why did Philip II Augustus declare King John’s French fiefs forfeited in 1202?

In 1202, Philip II Augustus declared King John’s French fiefs forfeited because John failed to appear before the French royal court to answer for his actions in Poitou.12

Following his marriage to Isabella of Angoulême—who had been betrothed to Hugh IX de Lusignan—John faced a rebellion from the Lusignan family. The Lusignans appealed to Philip II, acting in his capacity as their overlord, to intervene. When Philip summoned John to court to address the dispute and John refused to attend, Philip utilized this legal pretext to pronounce the forfeiture of John's French holdings, including Normandy, Anjou, Maine, and Touraine, and subsequently moved to enforce the sentence militarily.123