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 V of Jerusalem kingdom, preceding Sibylla's claim. Baldwin V, aged 5, was crowned co-king. The succession crisis also prompted a mission to the west to seek assistance: in 1184, Patriarch Eraclius, along with Roger de Moulins, Grand Master of the Knights Hospitaller, and Arnaud de Toroge, Grand Master of the Knights Templar, travelled throughout the courts of Europe. Eraclius offered the kingship to both Philip II of France and Henry II of England: the former was the son of Louis VII, a first cousin of Baldwin V's father; the latter was a first cousin of Baldwin IV and Sibylla, and had promised to