Following in the difficult footsteps of Egbert, first-ever king of all England, was Aethelwulf, Egbert’s son, who took the throne of Wessex in 839. And as Egbert is known for being the first king of all England, Aethelwulf is known for being the first King of Wessex who really gave a up a lot of territory to the Northmen.
Seemingly in response to the death of Egbert, raiders from Denmark stepped up their forays into England proper, not settling for landing in just Kent but continuing their predecessors’ work by working their way inland, smashing they way to Canterbury and even London before being stopped at Surrey by Aethelwulf himself.
It wasn’t just Wessex and Kent, that bore the brunt of the raids, either: Lindesy and East Anglia had their share of scares, Mercia’s King Beorhtwulf had his military hat handed to him, and Northumbria’s King Redwulf was killed on the field of battle.
And for the first time, Danes spent the winter in England, on the Isle of Thanet, in 850. They did it again, at Sheppey, a few years later. Not long after that, they were there to stay, or some it seemed to the Saxon defenders at the time.
To historians looking back at these events, it might appear that the Danes were hitting everywhere at once and meeting no resistance. This is not true. The Saxons fought back and fought back bravely, winning important victories all along the coast. With the crutch of hindsight to guide us, we modern historians would conclude that the Saxons were only delaying the inevitable; but one could also argue that the eventual victory of Harold Godwinson over Harald in 1066 would put to rest Northmen invasions for good.
At any rate, historians looking at this period of time often conclude that the Northmen were so successful at hitting the Saxons along a wide swath of ferocity because they were mobile and because they could live off the land and their spoils. The settlements in Thanet and Sheppey only increased their ability to do so.
So back to Aethelwulf: He wasn’t really fighting all the time, mainly because the Danes weren’t attacking all the time. Aethelwulf found plenty of time to do his kingly duties of getting married and giving money to the church (following in his predecessors’ footsteps). He even found time to make a pilgrimage to Rome to see the Pope. His son Alfred was on this trip with him.
When the two returned, they found Aethelwulf’s eldest son, Aethelbald, in charge and not willing to give up the Wessex throne. Because he had the backing of the army, Aethelbald found himself keeping the title of King of Wessex, although a little prematurely. Old King Aethelwulf ruled in Kent and a few of the surrounding areas until his death in 858, when Aethelbald took over the whole of the kingdom.