Excerpts from Books and Wikipedia
"King Edward the Elder of England, son of King Alfred, defeats the Northumbrian Vikings at the Battle of Tettenhall; they never raid south of the River Humber again." [Wikipedia: Timeline of Middle Ages] "The Battle of Tettenhall (sometimes called the Battle of Wednesfield or Wodnesfeld) took place, according to the Anglo-Saxon Chronicle, near Tettenhall on 5 August 910. The allied forces of Mercia and Wessex met an army of Northumbrian Vikings in Mercia.
After successful raids by Danish Vikings, significant parts of northeastern England, formerly Northumbria, were under their control. Danish attacks into central England had been resisted and effectively reduced by Alfred the Great, to the point where his son, King Edward of Wessex, could launch offensive attacks against the foreigners. Edward was allied with the Mercians under his sister Æthelflæd, and their combined forces were formidable." [Wikipedia]