A large band of them landed, in the autumn of 851, on the island of Thanet where the Saxons themselves had landed four centuries before, and began very coolly to establish their winter quarters on English ground.

They succeeded in maintaining their stay during the winter, and in the spring were prepared for bolder undertakings still.
They formed a grand confederation, and collected a fleet of three hundred and fifty ships, galleys, and boats, and advanced boldly up the Thames.

They plundered London, and then marched south to Canterbury, which they plundered too.

They went thence into one of the Anglo-Saxon kingdoms called Mercia, the inhabitants of the country not being able to oppose any effectual obstacle to their marauding march.
Finally, a great Anglo-Saxon force was organized and brought out to meet them.

The battle was fought in a forest of oaks, and the Danes were defeated.