HistoryData
war1171

1171 battle during Norman invasion of Ireland

January 1, 1171

The failed siege halted the high king's bid to expel Anglo-Normans from Dublin, consolidating Norman control of Ireland's most strategic city.

Quick Facts

Year
1171
Category
war

Key Facts

Year
1171
Irish besieging force
60,000 men
Irish casualties (Norman sally)
1,500 killed
Siege outcome
Unsuccessful; Irish forces routed
Norman commander
Strongbow
Irish commander
Ruaidrí Ua Conchobair, High King of Ireland

By the Numbers

1,171
Year
60,000
Irish besieging force
1,500
Irish casualties (Norman sally)

Location

Map of Dublin, IrelandMap of Dublin, IrelandDublin, Ireland

Cause → Event → Consequence

Cause

Following the Anglo-Norman seizure of Dublin, the last high king of Ireland, Ruaidrí Ua Conchobair, sought to reclaim the city. He assembled a large coalition force of roughly sixty thousand men, determined to drive out the invaders and reassert native Irish authority over the kingdom's most important urban centre.

Event

Ua Conchobair divided his army into four encampments surrounding Dublin. Exploiting this dispersal, the Norman garrison commander Strongbow launched a night surprise attack directly against the high king's camp. The sudden assault killed approximately fifteen hundred Irish soldiers and caused the remainder of the besieging force to break and flee, ending the siege.

Consequence

The failure of the siege effectively secured Anglo-Norman dominance over Dublin and undermined the high king's authority. Strongbow, who had already repulsed an earlier Irish attempt on the city, consolidated his position. The defeat left the native Irish unable to dislodge the Normans from Dublin, accelerating the broader Norman establishment in Ireland.

Belligerents & Mobilization Analysis

Side A

1 belligerent

Anglo-Normans (Dublin garrison)
Key Commanders

Strongbow.

Side B

1 belligerent

High Kingdom of Ireland (besieging Irish forces)
Peak Mobilized Forces~60K
Estimated Casualties~2K
Casualty Rate2.5%
Forces vs Casualties ratio
0CasualtiesMobilized
Key Commanders

Ruaidrí Ua Conchobair.

Total Casualties (all sides)
1,500
Outcome
Anglo-Norman victory; Irish besieging army routed, siege lifted

Timeline Context

Timeline around 11711171116811691170117211731174siege-of-dublin-1171