History of the Peloponnesian War
Thucydides
Thucydides. The history of the Peloponnesian War, Volume 1-2. Dale, Henry, translator. London: Heinemann and Henry G. Bohn, 1851-1852.
who, on arriving in Macedonia first, found that the former thousand had just taken Therme, and were besieging Pydna.
So they also sat down before Pydna, and besieged it; but afterwards, having made terms and a compulsory alliance [*]( i. e. which they only made because they could not help it. Compare II. 70. 1, βρώσεως πέρι ἀναγκαίας Food which none but a starving man would eat. —Arnold) with Perdiccas, as they were hurried on by Potidaea and the arrival of Aristeus there, they withdrew from Macedonia;