The Holy Island of Lindesfarne, off the Northumberland coast of the UK, was an important centre of Celtic Christianity, until the Viking arrived.
The first documented Viking raid on Britain was on the 6th June 793 and it took place in Lindesfarne.
Muslim, Magyar, and Vikings invaded Europe in the 800s.
The huns
Personally, I have never been invaded by Vikings. They did cause a bit of trouble for my Irish relations, though.
1066
the Normans invaded the British in 1006
The vikings
Invaded England, but were defeated.
Humans
Vikings
vikings from Scandinavia, followed by the normans from France
The most notable invaders of Ireland in the 12th century were the Normans.