Whether in the previous expeditions the Dorians had assisted the Heraclidae, is a matter of dispute--it is not a matter of importance.
Whether these Heraclidae were really descendants of the Achaean prince, and the rightful heritors of a Peloponnesian throne, is a point equally contested and equally frivolous.

It is probable enough that the bold and warlike tribe of Thessaly might have been easily allured, by the pretext of reinstating the true royal line, into an enterprise which might plant them in safer and more wide domains, and that while the prince got the throne, the confederates obtained the country [125].

All of consequence to establish is, that the Dorians shared in the expedition, which was successful--that by time and valour they obtained nearly the whole of the Peloponnesus--that they transplanted the Doric character and institutions to their new possessions, and that the Return of the Heraclidae is, in fact, the popular name for the conquest of the Dorians.

Whatever distinction existed between the Achaean Heraclidae and the Doric race, had probably been much effaced during the long absence of the former among foreign tribes, and after their establishment in the Peloponnesus it soon became entirely lost.

But still the legend that assigned the blood of Hercules to the royalty of Sparta received early and implicit credence, and Cleomenes, king of that state, some centuries afterward, declared himself not Doric, but Achaean.
Of the time employed in consummating the conquest of the invaders we are unable to determine--but, by degrees, Sparta, Argos, Corinth, and Messene, became possessed by the Dorians; the Aetolian confederates obtained Elis.