No large cities grew up within its territory, and its chief places, such as Delphi and Elatea, were mainly of strategic or cultural importance.

In 457 BC an attempt to extend their influence to the headwaters of the Cephissus in the territory of Doris brought a Spartan army into Phocis in defence of the "metropolis of the Dorians".

The subsequent decline of Athenian land power had the effect of weakening this new connection; at the time of the Peloponnesian War Phocis was nominally an ally and dependent of Sparta, and had lost control of Delphi.

In return for this negligence the Thebans fastened a religious quarrel upon their neighbours, and secured a penal decree against them from the Amphictyonic synod (356 BC).

The Phocians, led by two capable generals, Philomelus and Onomarchus, replied to the penal decree by seizing Delphi and using its riches to hire a mercenary army.

Augustus instituted an Achaean synod (σύνοδος) comprising the dependent cities of Peloponnese and central Greece; this body sat at Argos and acted as guardian of Hellenic sentiment.