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, Margrave of Flanders support the emperor's son, Louis the Stammerer. During his life, Baldwin expanded his territory into one of the major principalities of Western Francia. He died in 879 and was buried in the Abbey of St-Bertin, near Saint-Omer. Baldwin was succeeded by his and Judith's son, Baldwin II (c. 866 – 918). The couple's first son, Charles, named after his maternal grandfather, died at a young age. His third son Raoul ("Rodulf") (c. 869 – murdered 896) became Count of Cambrai around 888, but he and his brother joined king Zwentibold of Lotharingia in 895. In 896, they attacked Vermandois and