He defeated the Danes at Edington in 877 and translated religious works like St. Gregory's Pastoral Care and Boethius' Consolation of Philosophy.  
His biographer Asser records that he first came to prominence in the service of Burgred and married Burgred's niece Ealhswith (eels-with).  His military success derived largely from a defense line of earth forts known as burhs and his decision to force citizens of adequate wealth to join the thegn (thain), a mounted infantry class.  He defeated the Danes at Edington in 877 and translated religious works like St. Gregory's Pastoral Care and Boethius' Consolation of Philosophy.  For 10 points - name this Anglo-Saxon king who kept the Danes at bay and sponsored scholarly works like the Anglo-Saxon Chronicle.
His biographer Asser records that he first came to prominence in the service of Burgred and married Burgred's niece Ealhswith (eels-with).  
Alfred the Great