#OTD in 585 BC.
A solar eclipse occurs, as predicted by the Greek philosopher & scientist Thales, while Alyattes is battling Cyaxares in the Battle of the Eclipse, leading to a truce.
How exactly Thales predicted the eclipse remains uncertain; some scholars assert the eclipse was never predicted at all. Others have argued for different dates, but only the eclipse of May 585 BC matches the conditions of visibility necessary to explain the historical event.