Guy of Lusignan
Baldwin IV, who suffered from lepromatous leprosy, had made his nephew (the only son of his sister, Sybilla by her first husband), Baldwin V, his heir and co-ruler, to prevent Sybilla's second husband, Guy of Lusignan, from mounting the throne. The High Court of Jerusalem stipulated that a committee of Western European rulers was entitled to choose between Sybilla and Isabella to succeed Baldwin V if he died before reaching the age of majority, but Sybilla and Guy of Lusignan were crowned soon after Baldwin V died in 1185. Guy's opponents tried to play Isabella and her husband off against him, but Humphrey did homage to the royal couple.