Baldwin IV, 13, becomes King of Jerusalem, with Raymond III, Count of Tripoli as regent and William of Tyre as chancellor.

Baldwin IV (1161–1185), known as the Leper King, was the king of Jerusalem from 1174 until his death in 1185. Baldwin ascended to the throne when he was thirteen despite having leprosy. He launched several attempts to curb the Egyptian ruler Saladin's increasing power. Much of his life was marked by infighting amongst the kingdom's nobles, and Baldwin himself was the only person capable of holding them together. Throughout his reign, and especially at the end of his life, Baldwin was troubled by his succession, working to select a suitable heir and prevent a succession crisis. Choosing competent advisers, Baldwin ruled a thriving crusader state and succeeded in protecting it from Saladin.

The king or queen of Jerusalem was the supreme ruler of the Kingdom of Jerusalem, a Crusader state founded in Jerusalem by the Latin Catholic leaders of the First Crusade, when the city was conquered in 1099. Most of them were men, but there were also five queens regnant of Jerusalem, either reigning alone suo jure, or as co-rulers of husbands who reigned as kings of Jerusalem jure uxoris.

Raymond III was count of Tripoli from 1152 to 1187. He was a minor when Nizari Assassins murdered his father, Count Raymond II of Tripoli. His cousin, King Baldwin III of Jerusalem, who was staying in Tripoli, made Raymond's mother, Hodierna of Jerusalem, regent. Raymond spent the following years at the royal court in Jerusalem. He reached the age of majority in 1155, after which he participated in a series of military campaigns against Nur ad-Din, the Zengid ruler of Damascus. In 1161 he hired pirates to pillage the Byzantine coastline and islands to take vengeance on Byzantine emperor Manuel I Komnenos, who had refused to marry his sister Melisende. He was captured in the Battle of Harim by Nur ad-Din's troops on 10 August 1164, and imprisoned in Aleppo for almost ten years. During his captivity, his cousin King Amalric of Jerusalem administered the county of Tripoli on his behalf.