Key Facts
- Duration
- 17 weeks (1 Jul – 25 Oct 1147)
- Defender population
- 60,000 families at time of siege
- Citadel defenders reported
- 154,000 men (excluding women and children)
- Crusader departure point
- Dartmouth, Devon, Kingdom of England
- Later capital status
- Lisbon became capital of Portugal in 1255
Strategic Narrative Overview
The siege commenced on 1 July 1147. Lisbon's population had swelled with refugees from nearby fallen Christian cities such as Santarém. The crusaders and Portuguese forces encircled the city, cutting off supplies. Over seventeen weeks, the defenders endured severe hunger. The city's large garrison proved unable to break the blockade, and repeated Almoravid resistance gradually gave way as starvation weakened the defenders' capacity to hold out.
01 / The Origins
The fall of Edessa in 1144 prompted Pope Eugene III to call for a new crusade in 1145 and 1146. In spring 1147, the Pope extended crusading authorization to the Iberian Peninsula. A contingent of Northern European crusaders departing Dartmouth in May 1147 was forced by weather to stop at Porto, where Afonso I of Portugal, who had declared himself king in 1139, persuaded them to assist in attacking Lisbon, then held by the Almoravid dynasty.
03 / The Outcome
The rulers of Lisbon agreed to surrender on 24 October 1147, primarily due to famine within the walls. The city was formally taken on 25 October. Most crusaders settled in Lisbon rather than continuing to the Holy Land, though some sailed on to the Levant. The conquest removed Almoravid control of Lisbon permanently, incorporating it into the Kingdom of Portugal, which eventually made Lisbon its capital in 1255.
Belligerents & Mobilization Analysis
Side A
2 belligerents
Afonso I of Portugal.
Side B
1 belligerent
Kinetic Engagement Axis
Scroll horizontally to view full axis. Events plotted relatively.