The Battle of Aclea occurred in 851 between the West Saxons led by Æthelwulf, King of Wessex from 839 to what year, and the Danish Vikings?
Æthelwulf Æthelwulf (Old English for "Noble Wolf"; died 13 January 858) was King of Wessex from 839 to 858. In 825, his father, King Egbert, defeated King Beornwulf of Mercia, ending a long Mercian dominance over Anglo-Saxon England south of the Humber. Egbert sent Æthelwulf with an army to Kent, where he expelled the Mercian sub-king and was himself appointed sub-king. After 830, Egbert maintained good relations with Mercia, and this was continued by Æthelwulf when he became king in 839, the first son to succeed his father as West Saxon king since 641.
Ealdwulf of East Anglia Ealdwulf (or Aldwulf) was king of East Anglia from 663 to around 713. His forty-nine year reign was extraordinary in length, with only Æthelbald of Mercia and Offa of Mercia having comparable longevity. Little is known of Ealdwulf, but his long rule reflects the success of alliances formed in the decades before his ascension. During his reign, East Anglia experienced a long period of stability and growth, not least in its commercial centre at Gipeswic (now modern Ipswich).