all the little kingdoms that wanted to be bigger
In the south there was a gent from a royal house in Wessex called Alfred who was very bad in the kitchen & 4ever burning cakes. He rallied his peeps & the peeps of the rest of the little kingdoms & said tally-ho, let's push those Vikings into the sea from whence they came! He got to be called Alfred the Great for doing such & was the biggest of the little kings. If you were a rellie of Alfred, you were set for life. Peeps kept wanting to crown you king & such.
The Vikings for the most part had retreated across the English Channel to Normandy (so called b/c they were Norsemen, you understand, as they mostly were from Norway in Scandinavia, tho there were some from Denmark & Sweden, too) & started speaking French & being Catholic to fit in. All that nonsense on the islands of mist & fog & rain just weren't worth it to em. B/c of all that fighting & marrying to make peace & inbreeding there was hopelessly snarled family trees & they were all related somehow. So when the very last of Alfred's line, Edward the Confessor (he was quite the holy gent & built Westminster Abbey just in time to get buried in it), appeared incapable of producing more little cake-burners to be king, there was much speculation all around. Some peeps said Edward promised his throne to a kinsman called Harold Godwineson. But then Harold had an unfortunate shipwreck on Normandy's shores & the Duke of Normandy, one William the Bastard (his parents weren't married so that's what he was), was said to have squeezed Harold to give over the throne of England to him when Edward cocked up his toes.
Well, Edward did & Harold promptly crowned his good self as one would, thumbing his nose at those Normans. William was unfussed w/ this rudeness & gathered up a nice invasion force for what would henceforth be known as the Norman Conquest....
the Bayeux Tapestry picturing the invasion force