– 585 B.C.
The Medes and the Lydians were at war. The two kings were fighting over land and revenge for an act that had been carried out in revenge for another act that had been carried out... Well, you get the idea. Everybody was acting badly, and soldiers had been battling it out on behalf of their kings for FIVE YEARS!
Then the gods stepped in.
The gods made day into night to show their displeasure, and the battle stopped.
Somehow the two sides managed to arrange a truce. A boundary line was agreed on. One king's daughter married the other king's son to make sure the truce lasted.
Of course, what stopped the battle on this day almost 2,500 years ago wasn't a miracle created by the many Lydian gods or the one Median god. It was a total solar eclipse. Total solar eclipses are very rare but also completely normal and (nowadays) well understood.
Basically, the battle site just happened to be in the moon's shadow.
Because we can very accurately calculate the dates of solar eclipses, this battle is one of the earliest events that modern historians can pinpoint with a precise date.