Battle of Thermopylae - Strategic and Tactical Considerations

Strategic and Tactical Considerations

From a strategic point of view, by defending Thermopylae, the Greeks were making the best possible use of their forces. As long as they could prevent further Persian advance into Greece, they had no requirement to seek a decisive battle, and could thus remain on the defensive. Moreover, by defending two constricted passages (Thermopylae and Artemisium), the Greeks' inferior numbers became less problematic. Conversely, for the Persians the problem of supplying such a large army meant that the Persians could not remain in the same place for too long. The Persians must therefore retreat or advance; and advancing required the pass of Thermopylae to be forced.

Tactically, the pass at Thermopylae was ideally suited to the Greek style of warfare. A hoplite phalanx would be able to block the narrow pass with ease, with no risk of being outflanked by cavalry. In the pass, the phalanx would have been very difficult to assault for the more lightly armed Persian infantry. The major weak point for the Greeks was the mountain track which led across the highland parallel to Thermopylae, and which would allow their position to be outflanked. Although probably unsuitable for cavalry, this path could easily be traversed by the Persian infantry (many of whom were versed in mountain warfare). Leonidas was made aware of this path by local people from Trachis, and he positioned a detachment of Phocian troops there in order to block this route.