…on the Greek mainland, notably at Lerna.

Seal usage, and possibly even writing, are also known on the Greek mainland, notably at Lerna, and …

The Greek mainland is disrupted again around the beginning of the second millennium BCE with new levels appearing at sites such as Lerna in the Argolid and ...

Invaders coming from the Balkans apparently reach the Peloponnesus around 1900 and leave traces at Lerna.

These northerners may speak an Indo-European language, perhaps an early form of Greek.

…Aratus declines the generalship, and when both Athens and the Aetolian League turn down their appeals, they sue Cleomenes for peace Initially, Cleomenes makes only minor requests of the Achaean delegates, but as the talks progress, Cleomenes' demands become greater and he eventually insists that leadership of the League be surrendered to him.

In exchange, he will return to the Achaeans the prisoners and strongholds he has seized.

The Achaeans invite Cleomenes to Lerna, where they are holding council.

While marching there, Cleomenes drinks too much water, which causes him to lose his voice and cough up blood—a situation that forces Cleomens to return to Sparta.

The Achaean League, having successfully accomplished the expulsion of the Macedonians and the restoration of Greek rule in the Peloponnese in about 228 BCE, now faces the danger of complete disintegration before the assaults of the Spartan king Cleomenes III, who aims also at control of the Peloponnese and whose reforms Achaean leader Aratus of Sicyon opposes adamantly.

Possessed of few allies after its defeat at Hecatobaeum in 226, the Achaean League had been close to accepting Cleomenes as its leader, but instead concluded a peace treaty with Sparta.

The defeated League begins to disintegrate in 225, leaving Sparta and Macedon the sole contestants for control of Greece.

Aratus and the Achaean League are allowed to retain a shadow of independence, but no more than this.

The league, however, remains intact.

Executive power lies with the Council, which seems to have been a large body constituting a kind of representative government.