According to the Greek historian Herodotus, a solar eclipse, accurately predicted by Thales of Miletus, abruptly ended the Battle of Halys between the Lydians and the Medes.

This article concerns the period 589 BC – 580 BC.

Herodotus was a Greek historian and geographer from the Greek city of Halicarnassus, under Persian control in the 5th century BC, and a later citizen of Thurii in modern Calabria, Italy. He wrote the Histories, a detailed account of the Greco-Persian Wars, among other subjects such as the rise of the Achaemenid dynasty of Cyrus. He has been described as "The Father of History", a title conferred on him by the ancient Roman orator Cicero.

The eclipse of Thales was a solar eclipse in the early 6th century BC that was, according to the ancient Greek historian Herodotus, accurately predicted by the Greek philosopher Thales of Miletus. If Herodotus' account is accurate, this eclipse is the earliest recorded as being known in advance of its occurrence. The only solar eclipse matching the presumed place, era, and conditions of visibility necessary to explain the historical event is the eclipse of 28 May 585 BC.

Thales of Miletus was an Ancient Greek pre-Socratic philosopher from Miletus in Ionia, Asia Minor. Thales was one of the Seven Sages, founding figures of Ancient Greece.

Lydia was an Iron Age kingdom situated in western Anatolia, in modern-day Turkey. Later, it became an important province of the Achaemenid Empire and then the Roman Empire. Its capital was Sardis.