| Conflict: | Battle of Sandwich |
| Partof: | the Viking invasions of England |
| Date: | 851 |
| Place: | Sandwich, England |
| Result: | Kentish victory |
| Combatant1: | Kentishmen |
| Combatant2: | Vikings |
| Commander1: | Æthelstan |
| Commander2: | Unknown |
| Strength1: | Unknown |
| Strength2: | More than nine ships |
| Casualties1: | Unknown |
| Casualties2: | Nine ships lost |
The Battle of Sandwich in 851 was the first known naval battle in English history. It was a Kentish victory against a Danish Viking fleet.
In 851 King Æthelwulf of Wessex scored a major victory at the battle of Aclea over an army drawn from 350 Danish ships. He had appointed his eldest son Æthelstan under-king of Kent, and in the same year Æthelstan and his ealdorman Ealhhere defeated a Danish fleet off Sandwich in Kent.[1]
The Anglo-Saxon Chronicle recorded under 851 that: "King Æthelstan and Ealdorman Ealhhere fought in ships, and slew a great army at Sandwich in Kent, and captured nine ships, and put the others to flight.[2]
. Frank Stenton. 244. 1971. Anglo-Saxon England. Oxford University Press. Oxford, UK. 3rd. 1943. 978-0-19-280139-5.