From The Telegraph:
Some experts highlighted an entry in the Anglo-Saxon Chronicle which refers to a “red crucifix” seen in the night sky, but this occurred in 776 – a year too late – and does not explain why no remnants of the event have since been detected by astronomers.
From Roger of Wendover regarding 794 AD:
“In the year of our Lord 794, Humbert, archbishop of Lich field, died, and was succeeded by Higbert. The same year dreadful prodigies terrified the miserable English nation ; for fearful thunderbolts and horrible fiery dragons were seen passing through the air, foreboding a mighty famine and dreadful slaughter of the people. For the Danes with the Norwegians committed sad havoc among the people of Northumberland and of Lindesfarne, destroying the churches of Christ with their inmates. The island of Lindisfarne, which has an extent of eight miles or more, contains a noble monastery, in which was buried the illustrious father, bishop Cuthbert, with other prelates, his most holy successors. Now the Lindis is a rivulet, flowing into the sea, and is about two feet in width at low tides, but at high tides it cannot be seen.”
From the Anglo-Saxon Chronicles with regard to ~793 AD:
“In this year dire portents appeared over Northumbria and sorely frightened the people. They consisted of immense whirlwinds and flashes of lightning, and fiery dragons were seen flying in the air. A great famine immediately followed those signs , and a little after that in the same year, 8 June, the reavers of the heathen men miserably destroyed God’s church in Lindisfarne, with plunder and slaughter. And Sicga died on 22 February.”