HistoryData
war851

Battle between the West Saxons and the Vikings in 851

January 1, 0851

A decisive 851 West Saxon victory over Danish Vikings, described in the Anglo-Saxon Chronicle as the greatest slaughter of a Viking force heard of to that date.

Quick Facts

Year
851
Category
war

Key Facts

Year
851
Viking fleet size
350 ships ships
West Saxon commander
King Æthelwulf of Wessex
West Saxon co-commander
Æthelbald, son of Æthelwulf
Probable location
Ockley or Oakley, Surrey/Hampshire
Meaning of Aclea
Oak Field (per Asser)

Location

Surrey, England

Cause → Event → Consequence

Cause

A Danish Viking force of roughly 350 ships sailed into the Thames estuary, sacking Canterbury and London and routing Beorhtwulf, King of Mercia. The Vikings then crossed the Thames southward into Surrey, bringing them into direct conflict with the West Saxon kingdom under Æthelwulf.

Event

King Æthelwulf and his son Æthelbald led the West Saxon army against the Danish force at Aclea, a location recorded in Surrey but whose precise site—possibly Ockley in Surrey or Oakley in Hampshire—remains unidentified. The Anglo-Saxon Chronicle records the battle as producing the greatest slaughter of a Viking raiding army known up to that time.

Consequence

The West Saxons secured a decisive victory, halting the Viking advance through southern England. The battle demonstrated that large Viking fleets could be defeated in open battle, and it reinforced Wessex's military standing among the Anglo-Saxon kingdoms at a time of intensifying Scandinavian raids.

Belligerents & Mobilization Analysis

Side A

1 belligerent

West Saxons (Wessex)
Key Commanders

Æthelwulf, King of Wessex, Æthelbald (son of Æthelwulf).

Side B

1 belligerent

Danish Vikings
Outcome
Decisive West Saxon victory; described as the greatest slaughter of a Viking raiding army recorded to that date

Timeline Context

Timeline around 851851848849850852853854First recorded naval battle in English history851 battle between the Duchy of Brittany and West Franciabattle-of-aclea-851