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 of Luxembourg good terms with the Capetian court of France. He was only twenty-two years of age when elected Archbishop of Trier in 1307. In 1308, he was consecrated bishop by Pope Clement V in Poitiers. He quickly became one of the most influential princes in Germany, influencing the election that year of his brother Henry VII as King and Holy Roman Emperor. From 1310 to 1313, Baldwin accompanied Henry in Italy, where he was crowned emperor in Rome on 29 June 1312. In the election which followed Henry's early death the next year, Baldwin lent his support to Louis the Bavarian.