Follow the action through four phases. Positions and movements are illustrative; the notes distinguish evidence from reconstruction.
SCHEMATIC RECONSTRUCTIONPHASE 1 / 4
Greek coalition Persian-led coalition→ Movement / pressure⇢ Reconstructed route
PHASE 01
The coalition holds the pass
A Greek coalition under Leonidas occupies the constricted coastal route at Thermopylae, repairing a wall across the passage. Spartans serve alongside contingents from the Peloponnese and central Greece, while Phocians guard a mountain route above the pass. Persian forces approach from the Malian side. The Greek fleet operates separately at Artemisium as part of the broader defensive plan. The ancient sea lay much closer to the mountain front than it does today; sediment deposition and other landscape changes complicate reconstruction of the corridor the armies encountered.
What remains uncertain: The ancient shoreline, precise wall location and contingent frontages require reconstruction. Modern roads and monuments do not establish ancient battle lines.