On this date, a solar eclipse occurred that literally scared Louis the Pious, Holy Roman Emperor and King of the Franks, to death.
The third son of Charlemagne, Louis the Pious inherited a vast empire when his father died in 814. His reign was marked by dynastic crises and fierce rivalry between his sons. A deeply religious man who earned his nickname by performing penance for his sins, Louis reportedly became terrified of an impending punishment from God after witnessing a solar eclipse that lasted six minutes. According to legend, this caused him to waste away and eventually die on 20 June 840. His death plunged his fractured kingdom into a civil war that ended with the historic Treaty of Verdun, dividing Western Europe into the three major areas we now know as France, Germany, and Italy.
- Vita Hludovici Imperatoris (The Life of the Emperor Louis), by Astronomus (ca. 840 C.E.)