Passing over these mountains, with the paeonians on his right and the Sintians and Maedians on the left, he finally arrived at Doberus, in paeonia, losing none of his army on the march, except perhaps by sickness, but receiving some augmentations, many of the independent Thracians volunteering to join him in the hope of plunder; so that the whole is said to have formed a grand total of a hundred and fifty thousand.
"The History of the Peloponnesian War"
Thucydides
However, Pompey having a desire to confirm and keep him in the same mind, marched forwards for Petra, an expedition not altogether irreprehensible in the opinion of many; who thought it a mere running away from their proper duty, the pursuit of Mithridates, Rome's ancient and inveterate enemy, who was now rekindling the war once more, and making preparations, it was reported, to lead his army through Scythia and paeonia, into Italy.
"Plutarch-Lives-of-the-noble-Grecians-and-Romans"
Clough, Arthur Hugh
The earliest historical account of such habitations is that given by Herodotus of a Thracian tribe, who dwelt, in the year 520 B.C., in Prasias, a small mountain-lake of paeonia, now part of modern Roumelia.
"The Antiquity of Man"
Charles Lyell