A historian of military intelligence presents a revelatory account of ancient Greek battle tactics, including the use of espionage and irregular warfare. There are two images of warfare that dominate Greek history. The better known is that of Achilles, the Homeric hero skilled in face-to-face combat and outraged by deception on the battlefield. The alternative model, also taken from Homeric epic, is Odysseus, ‘the man of twists and turns’ who saw no shame in winning by stealth, surprise or deceit. It is common for popular writers to assume that the hoplite phalanx was the only mode of warfare used by the Greeks. The fact is, however, that the use of spies, intelligence gathering, ambush, and surprise attacks at dawn or at night were also a part of Greek warfare. While such tactics were not the supreme method of defeating an enemy, they were routinely employed when the opportunity presented itself.