The biography of Baldwin IV, known as the Leper King, began in Jerusalem shortly before his father, Amalric I, ascended the throne. Baldwin was born in 1161, and his early years were marked by the annulment of his parents’ marriage on the grounds of consanguinity. Five years later, in 1167, his father remarried the Byzantine princess Maria Comnena, who would later give birth to Baldwin’s half-sister, Isabella.
A tragic turning point came in 1170, when the young prince’s education was entrusted to the famous historian William of Tyre. During their lessons, William noticed a disturbing symptom: while playing with other boys, Baldwin felt no pain when pinched. William was the first to suspect the terrible disease that would define the king’s life. His fears were confirmed Baldwin had contracted leprosy, which gradually disfigured his body and led to early blindness.
On 11 July 1174, King Amalric I died, and just four days later, on 15 July, thirteen-year-old Baldwin was crowned. Because of his youth and illness, he could not rule independently, and power passed temporarily to regents. The kingdom’s seneschal, Miles de Plancy, first declared himself regent, but soon the position was taken by Count Raymond III of Tripoli, Baldwin’s cousin. The mysterious death of de Plancy solidified Raymond’s control.
It soon became clear that Baldwin would leave no heirs and that his reign would be brief. The court’s attention turned to his sisters, Sibylla and Isabella, upon whom the future of the kingdom depended. Sibylla was raised in a convent at Bethany, while Isabella grew up with her mother in Nablus. In 1176, to secure the royal succession, Raymond III arranged Sibylla’s marriage to William of Montferrat, a relative of both the kings of France and England. The marriage was short-lived: William died of malaria in 1177, leaving Sibylla pregnant. Her son, the future King Baldwin V, was born several months later.
In 1177 Baldwin, now of age, assumed full royal authority. He planned an invasion of Egypt and gained the support of the Byzantine Empire, but the year’s defining moment came on the battlefield. In November 1177 Sultan Saladin’s army invaded the Kingdom of Jerusalem, besieging Ramla, Lydda, and Arsuf. Despite his disease, Baldwin united with the Templars and, on 25 November, won a stunning victory at the Battle of Montgisard one of the most remarkable feats of the teenage king.
In the years that followed, Baldwin waged an unending war against the Muslims. In 1179, despite the king’s personal bravery, his forces were defeated near the fortress of Mezzeh (Mesaphat). Baldwin again showed courage, being carried from the field by his knight. That same year disaster struck at the fortress of Jacob’s Ford, where Saladin annihilated the Templar garrison a grave blow to Christian defenses.
In 1180 a brief respite came when Saladin concluded a two-year truce with Baldwin, allowing the king to focus on dynastic matters.
That summer Baldwin sought to strengthen his dynasty and curb Raymond’s influence by marrying his sister Sibylla to Guy de Lusignan, a powerful baron and vassal of the English crown. He also betrothed his younger sister Isabella to Humphrey IV of Toron, lord of Krak (des Moab), thus cementing an alliance with an influential noble house.
By 1183 Baldwin’s health had deteriorated sharply: he was completely blind and could scarcely walk. He appointed Guy de Lusignan as regent but soon regretted it. When Saladin besieged the fortress of Krak during Isabella’s wedding festivities, Guy failed to act decisively, allowing the enemy to withdraw unchallenged. Furious, the king stripped him of the regency.
Realizing his end was near, Baldwin named his five-year-old nephew his namesake Baldwin V, Sibylla’s son as co-ruler. In November 1183 the child was crowned, with Raymond III again acting as regent, trusted more than the discredited Guy. Baldwin even sought to annul Sibylla’s marriage to Guy but died before the process could be completed.
Baldwin IV died on 16 March 1185 at the age of twenty-four, exhausted by disease and the ceaseless intrigues of his court. His death marked the beginning of a new and troubled chapter for the Kingdom of Jerusalem. As he had decreed, the crown passed to his nephew Baldwin V whose reign, too, would prove tragically short.
Baldwin IV entered history as a courageous and resolute monarch who, despite the ravages of leprosy, personally led his armies into battle and won victories over the formidable Saladin. His brief reign was filled with drama and heroism, yet it also set the stage for the final decline of the Crusader Kingdom of Jerusalem.
