Timoleon

But when the struggle came to swords and the work required skill no less than strength, suddenly, from the hills, fearful peals of thunder crashed down, and vivid flashes of lightning darted forth with them.

Then the darkness hovering over the hills and mountain summits came down to the field of battle, mingled with rain, wind, and hail. It enveloped the Greeks from behind and smote their backs, but it smote the Barbarians in the face and dazzled their eyes, a tempest of rain and continuous flames dashing from the clouds.