The Thessalians as well as the Macedonians were, as it appears, an Illyrian race, who subdued a native Greek population; but in this case the body of the interlopers was smaller, while the numbers and civilisation of the aboriginal inhabitants were considerable. Hence the Thessalians resembled the Greeks more than any of the northern races with which they were connected: hence their language in particular was almost purely Grecian, and indeed bore perhaps a greater affinity to the language of the ancient epic poets than any other dialect. But the chief peculiarities of this nation with which we are acquainted were not of a Grecian character. Of this their national dress, which consisted in part of the flat and broad-brimmed hat καυσία and the mantle (which last was common to both nations, but was unknown to the Greeks of Homer’s time, and indeed long afterwards, until adopted as the costume of the equestrian order at Athens), is a sufficient example. The Thessalians moreover were beyond a doubt the first to introduce into Greece the use of cavalry. More important distinctions however than that first alleged are perhaps to be found in their impetuous and passionate character, and the low and degraded state of their mental faculties. The taste for the arts shown by the rich family of the Scopadæ proves no more that such was the disposition of the whole people, than the existence of the same qualities in Archelaus argues their prevalence in Macedonia. This is sufficient to distinguish them from the race of the Greeks, so highly endowed by nature. We are therefore induced to conjecture that this nation, which a short time before the expedition of the Heraclidæ, migrated from Thesprotia, and indeed from the territory of Ephyra (Cichyrus) into the plain of the Peneus, had originally come from Illyria. On the other hand indeed, many points of similarity in the customs of the Thessalians and Dorians might be brought forward. Thus, for example, the love for the male sex (that usage peculiar to the Dorians) was also common among the Illyrians, and the objects of affection were, as at Sparta, called ἀΐται; the women also, as amongst the Dorians, were addressed by the title of ladies (δέσποιναι), a title uncommon in Greece, and expressive of the estimation in which they were held. A great freedom in the manners of the female sex was nevertheless customary among the Illyrians, who in this respect bore a nearer resemblance to the northern nations. Upon the whole, however, these migrations from the north had the effect of disseminating among the Greeks manners and institutions which were entirely unknown to their ancestors, as represented by Homer.
We will now proceed to inquire what was the extent of territory gained by the Illyrians in the west of Greece. A great part of Epirus had in early times been inhabited by Pelasgi, to which race the inhabitants of Dodona are likewise affirmed by the best authorities to have belonged, as well as the whole nation of Thesprotians; also the Chaonians at the foot of the Acroceraunian Mountains, and the Chones, Œnotri, and Peucetii on the opposite coast of Italy, are said to have been of this race. The ancient buildings, institutions, and religious worship of the Epirotes are also manifestly of Pelasgic origin. We suppose always that the Pelasgi were Greeks, and spoke the Grecian language, an opinion however in support of which we will on this occasion only adduce a few arguments. It must then be borne in mind, that all the races whose migrations took place at a late period, such as the Achæans, Ionians, Dorians, were not (the last in particular) sufficiently powerful or numerous to effect a complete change in the customs of a barbarous population; that many districts, Arcadia and Perrhæbia for instance, remained entirely Pelasgic, without being inhabited by any nation not of Grecian origin; that the most ancient names, either of Grecian places or mentioned in their traditions, belonged indeed to a different era of the dialect, but not to another language; that finally, the great similarity between the Latin and Greek can only be explained by supposing the Pelasgic language to have formed the connecting link. Now the nations of Epirus were almost reduced to a complete state of barbarism by the operation of causes, which could only have had their origin in Illyria; and in the historic age, the Ambracian Bay was the boundary of Greece. In later times more than half of Ætolia ceased to be Grecian, and without doubt adopted the manners and language of the Illyrians, from which point the Athamanes, an Epirote and Illyrian nation, pressed into the south of Thessaly. Migrations and predatory expeditions, such as the Encheleans had undertaken in the fabulous times, continued without intermission to repress and keep down the genuine population of Greece.