Son of Egbert, king of the West Saxons (802-839), Ethelwulf became king during a period when the Danes were raiding the English coast (begun 835), yet it wasn't until 851 when Ethelwulf, after an alliance with Mercia, was able to secure a victory over the Danish army at Aclea in Kent; this was followed with the cementing of the Mercian alliance by the marriage of his daughter to King Burgred (853), and his own marriage to the daughter of West Frankish king Charles II the Bald. A plan to depose him was carried out by rivals to the throne after his return from a Roman pilgrimage (856); reduced in power, he ruled several eastern provinces from Kent until his death in 858. He was succeeded by his eldest son, Ethelbald.
Ethelwulf was a devout man and interested in the well-being of the churches in his realm. His “Decimations” was a system whereby a tenth of royal revenue was given to thegns (officials) in the form of grants to be allocated to religious foundations as required.
Reference: “Anglo-Saxon Chronicle” trans. Anne Savage