Location information

Ephialtes

A Malian, who in B.C. 480, when Leonidas was defending the pass of Thermopylae, guided a body of Persians over the mountain path, and thus enabled them to fall on the rear of the Greeks.

Perseus: Harry Thurston Peck, Harpers Dictionary of Classical Antiquities (1898)
• http://www.perseus.tufts.edu/cgi-bin/ptext?doc=Per...