Strange glow recorded in the Middle Ages attributed to a superflare event of the sun

[Red]

"One dark winter night in 992 C.E.—as the English King Æthelred the Unready was forced to pay tribute to Viking invaders and Almanzor, Muslim ruler of Andalusia, ravaged his Christian enemies in northern Spain—the northern sky was lit up by an ethereal glow. A chronicler in Saxony (modern-day Germany) wrote that “light like the Sun shone from the North.” The heavens were “blood-red,” said another from Ulster in northern Ireland."



http://www.sciencemag.org/news/2016/12/mystery-glow-lit-night-sky-992-ce-explained