History of the Peloponnesian War
Thucydides
Thucydides, Vol. 1-4. Smith, Charles Foster, translator. London and Cambridge, MA: Heinemann and Harvard University Press, 1919-1923.
Upon his arrival at Naupactus, Demosthenes found that Oeniadae had already been forced by all the rest of the Acarnanians to join the Athenian alliance; he himself then raised all the allied forces in that district, and after first making an expedition against Salynthius and the Agraeans[*](cf. 3.111.4; 3.114.2.) and securing these, proceeded with his other preparations so as to be present at Siphae when needed.
About the same time in the course of this summer, Brasidas, who was on his way to Thrace with one thousand seven hundred hoplites, reached Heracleia in Trachis and sent forward a messenger to his friends at Pharsalus requesting them to conduct him and his army through. Accordingly he was met at Meliteia in Achaia by Panaerus, Dorus, Hippolochidas, Torylaüs, and Strophacus, who was proxenus of the Chalcidians, and then proceeded on his march. He was conducted by several Thessalians also, among whom were Niconidas of Larisa, a friend of Perdiccas.
Indeed, Thessaly was not in any case an easy country to traverse without an escort, and especially with an armed force; and among all the Hellenes alike to traverse the territory of neighbours without their consent was looked on with suspicion. Besides, the common people of Thessaly had always been well disposed to the Athenians. If, therefore, the Thessalians had not been under the sway of a few powerful men, as is usual in that country, rather than under a free democracy, Brasidas would not have made headway;
even as it was, he was confronted on his march, when he reached the river Enipeus, by other Thessalians belonging to the opposite party. These tried to stop him, warning him that he was doing wrong in proceeding without the consent of the whole people.