He ordered Hydarnes to take the "Immortals," and, guided by a native, to proceed along the path by night, and descend with early dawn into the rear of the Greeks, who would then be placed between two fires.

The operation was performed with complete success.

The Phocian guard, surprised at the summit, left the path free while they sought a place of safety.

The Greeks in the pass below, warned during the night of their danger, in part fled, in part resolved on death.

When morning came, Leonidas, at the head of about half his original army, moved forward towards the Malian plain, and there met the advancing Persians.