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The Crusades

Baldwin IV: the leper king who defeated Saladin

Jerusalem, 1161–1185 · The most heroic life of the Middle Ages

Jun 20, 2026 · 12 min
Baldwin IV, the leper king of Jerusalem, seated on the throne with his face veiled by leprosy, a golden crown and bandaged hands

Some lives defy all categories. That of Baldwin IV of Jerusalem is one of them. Crowned at thirteen, a leper from the age of nine, blind and paralysed at the end, he governed the most threatened kingdom in Christendom for more than a decade with a clarity and courage that none of his healthy contemporaries could match. And when he died, barely twenty-four years old, he left the throne in the hands of the only people capable of losing everything — and they did.

The dynasty: five kings named Baldwin

When Godfrey of Bouillon conquered Jerusalem in July 1099 at the head of the First Crusade, he refused the title of King of the Holy City — he would not wear a crown of gold where Christ had worn a crown of thorns. It was his brother Baldwin of Boulogne who, without such scruples, crowned himself Baldwin I in the year 1100, founding the dynasty that would rule the Kingdom of Jerusalem for nearly a century.

He was followed by Baldwin II (1118–1131), his cousin and one of the pillars of the young kingdom, who welcomed Hugues de Payens and his first nine knights into the Temple and saw the Templar Order born under his reign. Then came Baldwin III (1143–1163), who conquered Ascalon from the Egyptian Fatimids, and finally Baldwin IV (1174–1185), the most extraordinary of them all. Five kings with the same name. One single obsession: keeping alive the impossible dream of a Christian kingdom in the heart of Islam.

A boy, a diagnosis, a destiny

Baldwin IV was born in 1161, son of King Amalric I and Agnes of Courtenay. He was a sharp, intelligent and physically gifted child — his tutor, the historian William of Tyre, described him as an exceptionally brilliant pupil. It was William himself who discovered, when Baldwin was about nine years old, that the boy felt no pain when his right arm was pinched. Physicians were not slow to confirm the diagnosis: leprosy.

The disease would advance inexorably. First the right arm, then both hands, then the face. In time Baldwin would lose sight in one eye, then the other. In his final years he governed lying on a litter, his body wrapped in bandages, unable to ride a horse. And yet, for more than a decade, he was the man who kept the greatest military leader of medieval Islam at bay.

Montgisard, 1177: the miracle in the desert

On 25 November 1177, Saladin — the Ayyubid sultan who had reunified Egypt and Syria and dreamed of reconquering Jerusalem — was advancing northward with an army of twenty-five thousand men, convinced that the Christian kingdom lay defenceless. Baldwin IV was sixteen years old, his body already marked by leprosy, and he had fewer than five hundred knights and a few thousand infantry.

What happened at the Battle of Montgisard is one of the most extraordinary episodes in the history of the Crusading Wars. The young leper king, who could barely hold the reins with his bandaged hands, personally led the charge. The Saracen vanguard was surprised and destroyed. Saladin had to flee on horseback, leaving his dead on the field. He lost more than eight thousand men. The Kingdom of Jerusalem survived another day.

Saladin, who was a man of honour as well as a military genius, publicly acknowledged the defeat. And, according to the chronicles, he never forgot the young king who had defeated him in the desert with half his forces.

Battle of Montgisard, 1177: Baldwin IV on horseback raises his sword beside the True Cross as the Templar knights charge Saladin's army at sunset
Montgisard, 25 November 1177 · the leper king, aged sixteen, defeats Saladin

Governing with death overhead

What makes Baldwin IV truly unique is not merely the victory at Montgisard. It is his capacity to govern, with complete lucidity, a kingdom in a permanent state of war, surrounded by quarrelling nobles and newly arrived crusaders from Europe who understood nothing of local politics — all while his body progressively disintegrated.

Baldwin was fully aware that he would have no children. Leprosy and the treatments of the age made marriage and succession impossible. He knew he would die young and that the kingdom needed a succession plan. He therefore poured all his political energy into managing that succession — a problem that would ultimately destroy what he had built.

In 1180, in a moment of political weakness, he consented to the marriage of his sister Sibylla to an ambitious French noble freshly arrived from overseas: Guy de Lusignan. It would prove to be the most catastrophic decision of his reign.

Baldwin IV, too ill to ride, carried on a litter by Templar knights before the walls of Jerusalem at sunset, beneath banners bearing the cross of Jerusalem
Bedridden and almost blind, the king kept ruling, carried on a litter to the very end

Sibylla, Guy de Lusignan and the collapse

Sibylla of Jerusalem was intelligent, beautiful and unfortunately in love with Guy de Lusignan — a man described by contemporary chroniclers with devastating unanimity: handsome, chivalrous in appearance, and entirely unfit for government or war. The barons of the kingdom despised him. Baldwin himself eventually acknowledged his mistake and tried to annul the marriage and remove Guy from power, without fully succeeding.

Baldwin IV died in the spring of 1185, aged twenty-four, blind and consumed by disease. He had named as regent his nephew, the child Baldwin V, Sibylla's son from a previous marriage, under the tutelage of Count Raymond III of Tripoli. But Baldwin V would die barely a year later, in 1186. And then Sibylla, now a free widow, made a decision that would change history: she crowned herself Queen of Jerusalem, and immediately afterwards crowned Guy de Lusignan as king consort. The barons who opposed Guy could do nothing — the kingdom was Sibylla's, and Sibylla wanted Guy.

The Horns of Hattin: the end of the dream

On 4 July 1187, on the volcanic hills beside the Sea of Galilee known as the Horns of Hattin, Saladin destroyed the crusader army in the most decisive battle in the history of the Kingdom of Jerusalem. Guy de Lusignan had made a series of military decisions so catastrophically wrong that modern historians still debate whether they sprang from incompetence or treachery: he marched the entire army across arid terrain in the height of summer, without access to water, straight into the trap Saladin had set for him.

The True Fragment of the Holy Cross — the kingdom's most sacred relic, carried into battle as a symbol of divine protection — was captured by the Muslims. The Grand Master of the Templars, Gerard of Ridefort, was taken prisoner. Guy de Lusignan was captured and brought before Saladin, who offered him water and spared his life. That same day, however, Saladin had personally drawn his scimitar and beheaded the French lord Raynald of Châtillon — the lord of Kerak, guilty of attacking an Arab merchant caravan and murdering Saladin's own sister during the raid. It was a blood debt the sultan had been waiting years to settle, and the battle of Hattin had delivered it on a silver platter. Three months later, on 2 October 1187, Saladin entered Jerusalem.

What Baldwin IV had defended with his shattered body for more than a decade — the impossible equilibrium, the constant negotiation, the calculated resistance — was lost in a single summer day through the vanity and incompetence of the man his sister had chosen as king. The lesson history offers is cruel and direct: sometimes the sickest man in the room is the only one who thinks clearly.

Sources and references

There is no fiction in this article

It is all documented, and by the man who knew best: William of Tyre, archbishop and Baldwin's own tutor, who noticed the leprosy while playing with the child and wrote it down in his Historia rerum in partibus transmarinis gestarum. From there come the diagnosis, the reign, the victory at Montgisard on 25 November 1177 against a far superior army, the steady decline and the death at twenty-four. And from there comes what happened once he was gone: the throne passed to Guy de Lusignan, who in two years took the kingdom to the Horns of Hattin — with Reynald of Châtillon and Gerard de Ridefort carrying out what that inept king ordered. What no chronicle could record is what the boy behind the mask was thinking as he lost his fingers and went on commanding armies; but anyone who reads what he did —and what happened when he was no longer there— can work out what he was made of. The dialogue and that inner pulse are the novelist's: David S. Matrecano.

Frequently asked questions

How old was Baldwin IV when he died?

He died in the spring of 1185 aged just 24, blind and paralysed, consumed by leprosy after more than a decade on the throne.

How old was Baldwin IV when he was crowned?

He was crowned King of Jerusalem in 1174 at only 13, on the death of his father Amalric I.

Was Baldwin IV a Christian?

Yes. He was the Christian king of the Kingdom of Jerusalem, the Crusader state founded after the First Crusade of 1099.

Who defeated Saladin?

Baldwin IV defeated him at the Battle of Montgisard (25 November 1177), aged 16, with fewer than 500 knights against 25,000 men.

Who reigned after Baldwin IV?

His young nephew Baldwin V and then, after the boy's death, his sister Sibylla with Guy de Lusignan, who lost the kingdom at the Battle of Hattin (1187).

✠ Recommended reading ✠

The Blood of Jerusalem — Part 2

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David S. Matrecano
✠ David S. Matrecano ✠
Ibiza, March 2026

Italian writer based in Ibiza. Author of the sagas The Eight Crusades, Herodotus · Histories Reloaded and Roma Stupor Mundi.

DM
Per Aspera, Ad Astra.
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