Order is restored in Anatolia by the Lydians, a Thracian warrior caste who dominate the indigenous peasantry and derive their great wealth from alluvial gold found in the tributaries of the Hermus River (Gediz Nehri).

Such Lydian kings as Croesus control western Anatolia from their court at Sardis until their kingdom falls to the Persians in 546 BCE.

Geometry has so far consisted of rules that produce useful, approximate, but not always accurate results.

Greek philosophers from about 600 BCE begin developing general theorems for geometry (although ancient reports that Thales of Miletus developed the first theorems are now in dispute).

Greek philosophers such as Thales are aware of the peculiar electrical properties of amber and silk.

Amber, when rubbed with a piece of fur, acquires resinous electricity and develops the ability to attract small pieces of material such as feathers.

Thales used silk in similar experiments with static electricity. (The word electricity is derived from the Greek word “elektron,” meaning "amber.”

Thales, a student of Egyptian astronomy, in 586 BCE reportedly predicts the solar eclipse that occurs the following year.

One effect of the eclipse will be the cessation of the war between Lydians and Medians.

The Middle East: 585–574 BCE

Nebuchadnezzar's Babylonian Renaissance

Following the devastation of Babylon through repeated rebellions and conflicts with Assyrian rulers like Sennacherib and Ashurbanipal, Nebuchadnezzar II (r. ca. 605–562 BCE), one of the most renowned rulers of the Chaldean Dynasty, continues extensive restoration and reconstruction efforts begun by his father, Nabopolassar. Nebuchadnezzar seeks to transform Babylon into a city of unparalleled magnificence, surpassing even the grandeur of his military achievements. The city is fortified by a triple line of walls and divided by the Euphrates River, crossed by a robust bridge supported by streamlined, asphalt-covered brick piers designed to resist erosion.

Among his grand architectural projects are numerous temples dedicated to the Babylonian pantheon, the lavish royal palace finished with cedar-wood, bronze, gold, silver, and precious stones, and the legendary Hanging Gardens of Babylon, reputedly built for his Median wife, Queen Amytis, to ease her homesickness. Babylon's splendor is further adorned by the famed Ishtar Gate, part of a museum housing the trophies of Nebuchadnezzar’s conquests.

Prophetic Voices and Literary Developments

This era also witnesses significant developments in religious and literary traditions. The Hebrew prophet Jeremiah, active during this tumultuous period, preaches from Anathoth, near Jerusalem. Jeremiah advocates for moral reform, repentance, and a renewed relationship between humanity and God amid the Babylonian conquest of Judah. His deeply personal reflections, known as the "confessions of Jeremiah," appear in the first 25 chapters of the Biblical Book of Jeremiah, revealing the prophet's inner spiritual struggles. Jeremiah's prophecies and historical accounts significantly influence later biblical literature, notably the composition of the Deuteronomistic History found in the Hebrew scriptures.

Median-Lydian Rivalry and Diplomacy

In the same period, tension escalates between the Median Empire, under Cyaxares, and Lydia, under King Alyattes, triggered by territorial ambitions and personal animosity. The conflict culminates at the Battle of the Halys River (also called the Battle of the Eclipse) on May 28, 585 BCE. This encounter abruptly ends when a solar eclipse frightens both armies into believing it to be an omen from the gods. Negotiations, mediated by Babylonia and the Cilician kings, result in peace: the Halys River becomes the official boundary, and Alyattes’s daughter, Aryenis, marries Cyaxares's son, Astyages, sealing the treaty through marriage.

Astyages and the Median-Persian Dynamics

Astyages ascends the Median throne in 585 BCE upon his father Cyaxares's death. He inherits a vast empire stretching from western Iran into Anatolia, managing it alongside his two powerful brothers-in-law—Croesus of Lydia and Nebuchadnezzar of Babylon. Astyages strengthens Median control over Persia by subjugating various Iranian tribes. To further secure political alliances, Astyages arranges for his daughter, Mandane, to marry the Persian prince Cambyses I, a notable but politically unambitious figure from the minor Persian kingdom of Anshan.

This era, from 585 to 574 BCE, thus marks a period of significant political realignments, extensive cultural achievements, and religious introspection, shaping the historical trajectory of the Middle East profoundly.

Astyages, married to Aryenis, the sister of King Croesus of Lydia, to seal the treaty between the two empires, ascends the Median throne in 585 upon the death of his father Cyarxes later in the year.

He has inherited a large empire, ruled in alliance with his two brothers-in-law, Croesus of Lydia and Nebuchadnezzar of Babylon, whose wife, Amytis, Astyages' sister, is the queen for whom Nebuchadnezzar is said to have built the Hanging Gardens of Babylon.

Media’s King Cyaxares and Lydia’s King Alyattes war from 590, instigated by a Median attempt to take over Urartu.

Herodotus (Histories, 1.73-74) states that there were two reasons for the war; the two sides clashing interests in Anatolia, but also there was a motive of revenge.

Some Scythian hunters employed by the Medes who once returned empty-handed were insulted by Cyaxares.

In revenge the hunters slaughtered one of his sons and served him to the Medes.

The hunters then fled to Sardis, the capital of the Lydians.

When Cyaxares asked for the Scythians to be returned to him, Alyattes refused to hand them over; in response, the Medes invaded.

The two armies oppose each other at the Halys River (Turkish: Kızılırmak, "Red River") , the boundary between Asia Minor and the rest of Asia, and also the boundary between Pontos and Paphlagonia.

As the site of the Battle of Halys or Battle of the Eclipse on May 28, 585 BCE, between the Medes and the Lydians, it is the border between Lydia to the west and Media to the east.

Since renamed as the Battle of the Eclipse, this final battle of the five-year war between Lydia and Media ends abruptly due to a total solar eclipse; the eclipse was perceived as an omen, indicating that the gods wanted the fighting to stop.

A truce is hastily arranged.

The war ends end through negotiations by the ruler of Babylonia and the Syenneses, kings of Cilicia.

As part of the terms of the agreement, Alyattes's daughter Aryenis is married to Cyaxares's son Astyages, and the river Halys is declared to be the border of the two warring nations.

Since the exact dates of eclipses can be calculated, the Battle of the Eclipse is the earliest historical event of which the date is known with such precision.