491 BC
Year 491 BC was a year of the pre-Julian Roman calendar. At the time, it was known as the Year of the Consulship of Augurinus and Atratinus (or, less frequently, year 263 Ab urbe condita). The denomination 491 BC for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.
Events
By place
Greece
Darius I sends envoys to all Greek cities, demanding "earth and water for vassalage" which Athens and Sparta refuse.
The Greek city of Aegina, fearing the loss of trade, submits to Persia. The Spartan king, Cleomenes I tries to punish Aegina for its submission to the Persians, but the other Spartan king, Demaratus, thwarts him.
Cleomenes I engineers the deposing of Spartan co-ruler Demaratus (and his replacement by Cleomenes’ cousin Leotychidas) by bribing the oracle at Delphi to announce that this action was divine will. The two Spartan kings successfully capture the Persian collaborators in Aegina.