Alexander's conduct caused renewed intervention; in 364 he was defeated at Cynoscephalae by the Thebans, although the victory was dearly bought by the loss of Pelopidas, who fell in the battle.
At Cynoscephalae the Macedonian phalanx and the Roman legion for the first time met in open fight, and the day decided which nation was to be master of Greece and perhaps of the world.
In the great war of their Roman allies against Philip the federal troops took a prominent part, their cavalry being largely responsible for the victory of Cynoscephalae (197).
Polybius, for instance, gives the number of the slain at Cynoscephalae as 8000; the annalists raise it as high as 40,000 (Livy xxxiii.
He may just have remembered the battle of Cynoscephalae (197), and, as we have seen, he was actively engaged in the military and political affairs of the Achaean League.