It was not in the parts only on the other side of the isthmus, that the Æolian nation was powerful, but those on this side also were formerly Æolians. They were afterwards intermixed first with Ionians who came from Attica, and got possession of Ægialus,[10] and secondly with Dorians, who under the conduct of the Heracleidæ founded Megara and many of the cities in the Peloponnesus. The Iones were soon expelled by the Achæi, an Æolian tribe; and there remained in Peloponnesus the two nations, the Æolic and the Doric. Those nations then that had little intercourse with the Dorians used the Æolian dialect. (This was the case with the Arcadians and Eleians, the former of whom were altogether a mountain tribe, and did not share in the partition of the Peloponnesus; the latter were considered as dedicated to the service of the Olympian Jupiter, and lived for a long period in peace, principally because they were of Æolian descent, and had admitted into their country the army of Oxylus, about the time of the return of the Heracleidæ.[11]) The rest used a kind of dialect composed of both, some of them having more, others less, of the Æolic dialect. Even at present the inhabitants of different cities use different dialects, but all seem to Dorize, or use the Doric dialect, on account of the ascendency of that nation. Such then is the number of the Grecian nations, and thus in general are they distinguished from each other. I shall resume my account of them, and describe each nation in their proper order. 3. According to Ephorus, Acarnania is the commencement of Greece on the west, for it is the first country which lies contiguous to the Epirotic nations. As this author follows the coast in his measurements, and begins from thence, considering the sea the most important guide of topographical description, (for otherwise he might have placed the beginning of Greece in Macedonia and Thessaly,) so ought I, observing [CAS. 334] the natural character of places, to keep in view the sea as a mark by which I should direct the course of my description. The sea coming from Sicily spreads itself on one side towards the Corinthian Gulf, and on the other forms a large peninsula, the Peloponnesus, united to the mainland by a narrow isthmus.