What is now called Middle Albania, the Illyrian territory immediately north of Epirus, is much superior to the latter in productiveness.[8] Though mountainous, it possesses more both of low hill and valley, and ampler as well as more fertile cultivable spaces. Epidamnus and Apollonia formed the seaports of this territory, and the commerce with the southern Illyrians, less barbarous than the northern, was one of the sources[9] of their great prosperity during the first century of their existence,—a prosperity interrupted in the case of the Epidamnians by internal dissensions, which impaired their ascendency over their Illyrian neighbors, and ultimately placed them at variance with their mother-city Korkyra. The commerce between these Greek seaports and the interior tribes, when once the former became strong enough to render violent attack from the latter hopeless, was reciprocally beneficial to both of them. Grecian oil and wine were introduced among these barbarians, whose chiefs at the same time learned to appreciate the woven fabrics,[10] the polished and carved metallic work, the tempered weapons, and the pottery, which issued from Grecian artisans. Moreover, the importation sometimes of salt-fish, and always that of salt itself, was of the greatest importance to these inland residents, especially for such localities as possessed lakes abounding in fish, like that of Lychnidus. We hear of wars between the Autariatæ and the Ardiæi, respecting salt-springs near their boundaries, and also of other tribes whom the privation of salt reduced to the necessity of submitting to the Romans.[11] On the other hand, these tribes possessed two articles of exchange so precious in the eyes of the Greeks, that Polybius reckons them as absolutely indispensable,[12]—cattle and slaves; which latter were doubtless procured from Illyria, often in exchange for salt, as they were from Thrace and from the Euxine and from Aquileia in the Adriatic, through the internal wars of one tribe with another. Silver-mines were worked at Damastium in Illyria. Wax and honey were probably also articles of export, and it is a proof that the natural products of Illyria were carefully sought out, when we find a species of iris peculiar to the country collected and sent to Corinth, where its root was employed to give the special flavor to a celebrated kind of aromatic unguent.[13] [8] See Pouqueville, Voyage en Grèce, vol. i, chs. 23 and 24; Grisebach, Reise durch Rumelien und nach Brussa, vol. ii, pp. 138-139; Boué, La Turquie en Europe, Géographie Générale, vol. i, pp. 60-65. [9] Skymnus Chius, v, 418-425. [10] Thucydidês mentions the ὑφαντὰ τε καὶ λεῖα, καὶ ἡ ἄλλη κατασκευὴ, which the Greek settlements on the Thracian coast sent up to king Seuthês (ii, 98): similar to the ὑφασμαθ᾽ ἱερὰ, and to the χεριαρᾶν τεκτόνων δαίδαλα, offered as presents to the Delphian god (Eurip. Ion. 1141; Pindar, Pyth. v, 46).