Isabella I of Jerusalem tried to play Isabella and her husband off against him, but Humphrey did homage to the royal couple. Isabella was the daughter of Amalric, King of Jerusalem, by his second wife, Maria Comnena. Maria Comnena (who was a grandniece of the Byzantine Emperor, Manuel I Komnenos) married Amalric on 29 August 1171. Isabella was born before September 1172. Amalric died unexpectedly on 11 July 1174. His son by his first marriage, Baldwin IV, was crowned king two weeks later. Before long, it became obvious that Baldwin suffered from lepromatous leprosy. To secure the succession of the ailing king, his sister,
Baldwin I, Latin Emperor of this land. After Philip II of France took Baldwin's brother, Philippe of Namur, prisoner, Baldwin was forced to agree to a truce to ensure his safety. The Treaty of Péronne was signed in January 1200 on the condition that Baldwin receive the territories he had won during the war. Baldwin was made the vassal of Philip II, and the king returned portions of Artois to Baldwin. In this fight against the French king, Baldwin allied with others who had quarrels with Philip, including kings Richard I and John of England, and the German King Otto IV. A month after