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King Baldwin

“King Baldwin” most commonly refers to one of the medieval kings of Jerusalem from the House of Boulogne, especially Baldwin I and Baldwin IV.

By Ethan Anderson| Reviewed by Olivia Bennett, Standards & Fact-Checking Lead| Updated July 26, 2026|2 min read| Fact-checked

“King Baldwin” most commonly refers to one of the medieval kings of Jerusalem from the House of Boulogne, especially Baldwin I and Baldwin IV. Baldwin I founded and expanded the Kingdom of Jerusalem after the First Crusade, while Baldwin IV, known as the “Leper King,” ruled from 1174 to 1185 despite leprosy.

Baldwin I of Jerusalem

Baldwin I, also known as Baldwin of Boulogne, became king of Jerusalem in 1100. He is associated with the consolidation and expansion of the kingdom after the First Crusade. His reign lasted from 1100 to 1118.

Baldwin III of Jerusalem

Baldwin III ruled from 1143 to 1163. He is remembered for strengthening the kingdom and expanding its borders during the Crusader period.

Baldwin IV of Jerusalem

Baldwin IV ruled from 1174 to 1185. He became known as the “Leper King” because of the disease that affected him for most of his life. He became king at age 13 and spent much of his reign resisting Saladin’s power.

Historical significance

The Baldwin kings were major figures in the history of the Kingdom of Jerusalem and the wider Crusader states, shaping military, political, and territorial developments in the region.

Key facts

  • The name “King Baldwin” refers to several medieval kings of Jerusalem, not a single individual.
  • Baldwin I was the first king of Jerusalem and is widely associated with consolidating the new Crusader kingdom.
  • Baldwin IV ruled from 1174 to 1185 and was called the “Leper King” because of leprosy.
  • Baldwin IV became king at age 13 and spent much of his reign resisting Saladin’s power.
  • The reigns of the Baldwin kings are central to the history of the Crusader states in the Levant.

Frequently asked questions

Who was King Baldwin?
“King Baldwin” usually refers to one of several medieval kings of Jerusalem, especially Baldwin I or Baldwin IV.
Why was Baldwin IV called the Leper King?
Baldwin IV was called the “Leper King” because he suffered from leprosy during his reign.
Which Baldwin founded the Kingdom of Jerusalem?
Baldwin I is the Baldwin most closely associated with founding and consolidating the Kingdom of Jerusalem.
How long did Baldwin IV rule?
Baldwin IV ruled Jerusalem from 1174 until his death in 1185.
Was there more than one King Baldwin of Jerusalem?
Yes. The best-known rulers with this name include Baldwin I, Baldwin III, and Baldwin IV.

References

  1. Encyclopaedia Britannica — https://www.britannica.com/biography/Baldwin-I-king-of-Jerusalem
    Supports: Baldwin I as king of Jerusalem from 1100 to 1118; his role in expanding and securing the kingdom.
  2. Encyclopaedia Britannica — https://www.britannica.com/biography/Baldwin-IV-king-of-Jerusalem
    Supports: Baldwin IV as king of Jerusalem from 1174 to 1185 and his nickname as the Leper King.
  3. Wikipedia — https://www.wikiwand.com/en/articles/Baldwin_III_of_Jerusalem
    Supports: Baldwin III as king of Jerusalem from 1143 to 1163 and his significance in expanding the kingdom.
  4. Encyclopedia.com — https://www.encyclopedia.com/religion/encyclopedias-almanacs-transcripts-and-maps/baldwin-king-jerusalem
    Supports: Several kings of Jerusalem named Baldwin, including Baldwin I and Baldwin III.
  5. Wikipedia — https://en.wikipedia.org/wiki/Baldwin_IV_of_Jerusalem
    Supports: Baldwin IV became king at age thirteen, had leprosy, and reigned until 1185.