When the Social War broke out between Athens and its allies (357), Olynthus was at first in alliance with Philip. Subsequently, in alarm at the growth of his power, it concluded an alliance with Athens. Olynthus made three embassies to Athens, the occasions of Demosthenes's three Olynthiac Orations. On the third, the Athenians sent soldiers from among its citizens. After Philip had deprived Olynthus of the rest of the League, by force and by the treachery of sympathetic factions, he besieged Olynthus in 348. The siege was short; he bought Olynthus's two principal citizens, Euthycrates and Lasthenes, who betrayed the city to him. He then looted and razed the city and sold its population—including the Athenian garrison—into slavery. According to the latest researches only a small area of the North Hill was ever re-occupied, up to 318, before Cassander forced the population to move in his new city of Cassandreia.