Agis II, king of Sparta from about 427 BCE, invades the territory of Athens' ally Argos in 418 BCE while the Peace of Callias (421-415 BCE) is still in effect, but inexplicably makes a truce and withdraws after cutting the Argive army off from its city.

He escapes heavy penalties for his failure to press his advantage by promising more successful enterprises.

He receives his chance a few weeks later, when …

…the anti-Spartan and aggressive Alcibiades, who in 420 BCE had been named general for the first time, opposes the Nicias, who had negotiated the peace, forces a break with Sparta, and steers Athens into …

…the anti-Spartan alliance formed by the Peloponnesian city-states Argos, Elis, and Mantineia, all formerly in the Spartan camp.

The Spartan forces of King Agis crushingly defeat the alliance of Athens, Argos, Elis, and Mantineia at the Battle of Mantineia (418), in which the Athenian commander, Laches, is killed. (A dialogue of Plato's, on bravery, is known by his name.)

Astrology, which originated in ancient Babylonia, has spread from there to China, India, and the West, where different but related traditions have evolved.

The earliest known horoscope (incorporating the principles of mature occidental, or Western, astrology) dates from 409 BCE.

The Spartans had appointed one of their own, Clearchus, as governor of Byzantium; he rules Byzantium with such tyranny that the people open the city to Alcibiades' Athenian forces in 408, but Sparta regains possession in 405.

The Middle East: 417–406 BCE

Revolts in Cyprus and Anatolia

During this era, Cyprus sees significant political change as Evagoras, a descendant of Salamis' traditional Greek ruling family, rises to power around 411 BCE after overthrowing Phoenician control. Once established on the throne, Evagoras aligns his city-state with Athens, actively opposing Persian dominance. His reign signifies a resurgence of Greek influence in Cyprus and signals persistent resistance against Achaemenid rule in the region.

Meanwhile, in Anatolia, the strategically crucial city of Cyzicus, a longtime loyal member of the Delian League under Athenian hegemony, revolts against Athenian control in 411 BCE. This revolt illustrates the growing instability and shifting allegiances within Greek-held territories and Persian borderlands, reflecting broader geopolitical realignments during this tumultuous period.

Evagoras, a member of the traditional ruling family of the Greek city of Salamis in Cyprus, gains the throne in 411 after a period of Phoenician domination and allies his city with Athens against the Persians.

Cyzicus, which had joined the Delian League after the defeat of Xerxes and has remained loyal to Athens, revolts in 411 BCE.

Near East (417–406 BCE): Persian Administration of Yehud

Between 417 and 406 BCE, the Persian province of Yehud (formerly the kingdom of Judah) continues to be administered under Persian authority, marking a period of relative stability for the Jewish community. High priests, acting as regional governors under Persian oversight, manage local affairs, reflecting a balance of religious and political power.

A notable indication of local autonomy is the issuance of distinct coinage by the high priests of Yehud. These coins symbolize both a degree of administrative independence and the ongoing integration of Yehud within the broader Persian economic framework. The authority to mint their own coins allows the high priests not only to facilitate local commerce but also to reinforce their spiritual and secular leadership among the Jewish population.

This administrative and economic activity highlights the evolution of Yehud as a stable and structured province, maintaining its distinct cultural and religious identity while operating effectively within the expansive Persian Empire.