Humphrey IV of Toron, born in 1166, emerged as a prominent baron in the Kingdom of Jerusalem. He inherited the Lordship of Toron from his grandfather, Humphrey II, in 1179, and was also the heir to the Lordship of Transjordan through his mother, Stephanie of Milly. In a significant political move in 1180, he yielded Toron to King Baldwin IV of Jerusalem upon the king's engagement to his half-sister, Isabella.
Humphrey's marriage to Isabella took place in the autumn of 1183 at Kerak Castle, amidst the tumult of Saladin's siege. The wedding was marked by the intervention of King Baldwin IV and Count Raymond III of Tripoli, who successfully relieved the fortress during this critical moment. Following Baldwin IV's death, the barons of Jerusalem faced a succession crisis, leading to a controversial decision to proclaim Humphrey and Isabella as king and queen. However, Humphrey declined the throne, opting instead to pay homage to Sybilla and her husband, Guy of Lusignan.
In 1187, Humphrey was captured at the Battle of Hattin, where Saladin dealt a devastating blow to the Kingdom of Jerusalem's forces. His mother, Stephanie, negotiated his release by offering the fortresses of Oultrejordain to Saladin, although the garrisons of Kerak and Montréal resisted surrendering. Humphrey was eventually freed, but Kerak fell to Saladin's troops in late 1188, followed by Montréal in early 1189.
After the death of Queen Sybilla in 1190, the barons sought to marry Isabella to the military leader Conrad of Montferrat, leading to the annulment of Humphrey and Isabella's marriage, despite their protests. In 1191, Humphrey joined King Richard I of England's crusade, utilizing his fluency in Arabic to facilitate negotiations with Saladin's brother, Al-Adil. Humphrey IV of Toron passed away in 1198, leaving behind a legacy intertwined with the tumultuous history of the Crusader states.