Leonidas, a member of the Agiad house and married to Cleomenes' daughter, Gorgo, who possibly supports Cleomenes' aggressions against other Greek cities, in 490 succeeds his half-brother as one of Sparta's two kings.

The Messenians stage an unsuccessful anti-Spartan revolt from the fortress citadel of Mount Ithome in 490 BCE.

The First Persian War is brief.

Persia in the summer of 490, intending to punish Athens for its participation in a raid in Asia Minor, sends a force (small by Persian standards, about twenty thousand infantry and eight hundred cavalry, commanded by Datis, a Mede) that sails across the Aegean, stopping to capture the Ionian colony of Náxos, the largest of the Cyclades.

Hippias, the deposed Athenian tyrant who had taken refuge with the Persian governor at Sardis and is now a bitter old man, crosses the Aegean with the Persian army.

The seaborne invaders capture Náxos, treating the island with severity, …

…receive the submission of Andros, then continue to …

…Euboea, where they subjugate Carystus (modern Káristos) in the south and …

…destroy Eretria, enslaving and deporting its inhabitants as punishment for the five triremes sent in aid of the Ionians.

The Persians then sail south to …

…the Plain of Marathon northeast of Athens, a spot preselected by the Athenian Alcemeonid faction, led by Hippias, which hopes to be restored to power by the would-be conquerors. (The Peisistratids came originally from eastern Attica.)

The Persian army of twenty-five thousand men lands unopposed.

The Athenians are faced with the choice of marching out and confronting the Persians at Marathon or waiting for them at Athens; the decision is to be made by the Assembly.

Miltiades is well aware of the power of the Persian cavalry, which, once out on the open plain, will wreak havoc.

He is also anxious for a quick decision, because there are factions within Athens that will welcome a Persian victory in order to advance their own political ambitions.

His arguments persuade the Assembly, and the Athenian forces set out.

A runner is sent to Sparta, to seek the support of the Spartan army, but the pious Spartans reply that they will participate only at the conclusion of the sacred month of a religious festival six days later (when the moon is full).

A conflict then arises among the ten Athenian generals over whether to wait or to attack the Persians immediately.

The deciding vote is cast by the polemarchos (supreme military commander) Callimachus, whom Miltiades is able to persuade to immediate action.

The operational command of the army is to be held for one day in turn by each of the ten, but the four who have supported Miltiades surrender their right to command to him.

A Greek soldier named Pheidippedes runs (according to legend) the twenty-two and a half miles (thirty-six point two kilometers) from the Marathon battlefield to Athens, where he announces the overwhelming Greek victory over the Persians, collapses, and dies.

The Athenian army, force-marching to Athens to join the alerted citizenry, arrives in time to see the Persian fleet decline to land.

Hippias is said to have died at Lemnos on the journey home.

China’s so-called “Spring and Autumn Period” ends in 476 BCE (or, by some authorities, in 403 BCE).

After the king of Wú died during an invasion of Yuè (496 BCE), his son, King Fuchāi of Wú, had nearly destroyed the Yuè state, defeated Qí, and threatened Jìn.

In 482 BCE, King Fuchāi holds an interstate conference to solidify his power base, but Yuè captures the Wú capital.

Fuchāi rushes back but is besieged by the Yue forces.