A failed 1142 attempt to capture Lisbon by Portuguese and Anglo-Norman forces established a precedent for the successful 1147 Crusader siege.
Key Facts
- Year
- c. 1142
- Target city
- Lisbon (Almoravid-controlled)
- Initiating ruler
- King Afonso I Henriques of Portugal
- Primary sources
- De expugnatione Lyxbonensi; Chronica Gothorum
- Outcome
- Failed siege; outskirts destroyed, attackers withdrew
- Later consequence
- Precedent for the successful Siege of Lisbon in 1147
Location
Cause → Event → Consequence
Around 1142, Anglo-Norman crusaders en route to Jerusalem were invited by King Afonso I Henriques to join an assault on Almoravid-held Lisbon. The king sought external military support to take the strategically important city, which was heavily populated and well supplied.
The combined Portuguese and Anglo-Norman force attempted to besiege Lisbon but found themselves too few to sustain a prolonged siege. Unable to capture the city, the Christian forces instead destroyed its outskirts before withdrawing. The Anglo-Normans then continued to the Holy Land, while the Portuguese returned home.
The failure left Anglo-Norman crusaders dissatisfied with their Portuguese allies, complicating later negotiations before the 1147 Siege of Lisbon. Nevertheless, the episode provided Afonso Henriques a model for future crusader cooperation and likely prompted him to plan the capture of Santarém to cut Lisbon's river supply lines.
Belligerents & Mobilization Analysis
Side A
2 belligerents
Afonso I Henriques, William Vitalus (possible), Ralph Vitalus (possible).
Side B
1 belligerent