The Lion of Sparta by John Burke (Pan, 1961)

Another find in the dusty recesses of the Green Shed:

BARBARIC
SPLENDOUR

ELEMENTAL
SAVAGERY

SUPERB
HEROISM

The countless hordes of Asia surged onwards towards Greece--an irresistible wave spreading  fire, pillage and rapine.  Xerxes, King of Persia, had sworn to annihilate the Greek States.

But at Thermopylae waited Leonidas, King of Sparta--blocking the narrow pass with his immortal Three Hundred.

These were no ordinary men.  For Spartans there was no retreat, no surrender.  Their highest hope a glorious death.

This is the story of those men--and their women--and of the days which led them to Thermopylae, that desperate, glorious battle which changed the course of history.

"As filmed by 20th Century Fox starring Richard Egan"... another long-forgotten CinemaScope epic, starring an actor I've never heard of.  And yet, strangely enough, Ralph Richardson appears in a supporting role!