On this date, May 28, 585 BC, during battle of Halys, a solar eclipse occurred. Our ability to date this eclipse makes the battle of Halys perhaps the earliest event we can precisely date. According to Herodotus, the eclipse was predicted by Thales of Miletus, making it the first solar eclipse in history to be predicted.

From Herodotus’ The Histories, 1.73-1.74:

“Afterwards, on the refusal of Alyattes to give up his suppliants when Cyaxares sent to demand them of him, war broke out between the Lydians and the Medes, and continued for five years, with various success. In the course of it the Medes gained many victories over the Lydians, and the Lydians also gained many victories over the Medes. Among their other battles there was one night engagement. As, however, the balance had not inclined in favour of either nation, another combat took place in the sixth year, in the course of which, just as the battle was growing warm, day was on a sudden changed into night. This event had been foretold by Thales, the Milesian, who forewarned the Ionians of it, fixing for it the very year in which it actually took place. The Medes and Lydians, when they observed the change, ceased fighting, and were alike anxious to have terms of peace agreed on.”