The Achaean League, with Aratus of Sicyon as the leading spirit, gains strength by the inclusion of his city, and later other non-Achaean cities, on equal terms.

The league's activity initially centers on the expulsion of the Macedonians and the restoration of Greek rule in the Peloponnese.

The general is the annually elected head of the league's army, and a particular general cannot be immediately reelected.

The general, a post normally held by Aratus each alternate year after 245, heads the league's administrative board, whose ten members in turn preside over the various city-states' representative councils and assemblies.

These bodies of citizenry can vote on matters submitted to them by the general.

The minimum voting age in the assemblies is thirty years of age.

Under the Achaean League's federal constitution, its city-state members have almost complete autonomy within the framework of the league's central administration; only matters of foreign policy, war, and federal taxes are referred to the general and the board for decision making.