The sack of Lindisfarne Abbey is considered by many historians to begin the period of the Viking invasions of England. It is mentioned briefly in the Anglo-Saxon Chronicle as such:
This year came dreadful fore-warnings over the land of the Northumbrians, terrifying the people most woefully: these were immense sheets of light rushing through the air, and whirlwinds, and fiery dragons flying across the firmament. These tremendous tokens were soon followed by a great famine: and not long after, on the sixth day before the ides of January in the same year, the harrowing inroads of heathen men made lamentable havoc in the church of God in Holy-island, by rapine and slaughter.
While this was not the first time the Vikings came to England, it is certainly the most memorable. This invasion would spark a series of subsequent invasions that lasted for the next few centuries as the Norsemen attempted to conquer the entirety of England.