Much of the history of Phlious involves a constant dispute between democratic and oligarchic factions. Although a consistent ally of Sparta, the latter city rarely forced its brand of government on them.
Phlious was a relatively small city, with roughly five thousand men of fighting age. Yet the exiles of whichever faction was not in power often induced Sparta to intervene on their behalf.
The city often suffered from invasions by Athens, Thebes, and Sikyon that were generally intended against their more powerful neighbor, Sparta. However, they remained remarkably steadfast in support of the Lakedaimons.
Phlious was the birthplace of Pratinas, who was a famed playwright who competed against Aeschylus and who was credited with separating satiric from tragic drama. Only fragments of his work are preserved.
The Battle of Thermopylae. Soldiers from Sparta, Mantinea, Tegea, Orchomenos (Arkadia), Corinth, Phlious, Thespiai, Phokis, Opuntian Lokris, and other cities are overrun by the Persians at a huge cost.