The English Benedictine monk Eilmer of Malmesbury saw Halley’s comet as a young boy in 989.

When he saw it again 76 years later, he declared: “You’ve come, have you? … You’ve come, you source of tears to many mothers. It is long since I saw you; but as I see you now you are much more terrible, for I see you brandishing the downfall of my country.”

The year was 1066. That October, with the Battle of Hastings, the Normans began their conquest of England.