Battle of Hemmingstedt, Circa 1500 (Between the Danes and the Peasant Republic of Dithmarschen), the Germanic Thermopylae?

 

In several respects it was; a) the overwhelming numerical advantage of the Danes over the peasants was akin to that of the Persians over the Greeks (courage, anybody?) and b) it put on full display the distinct advantage of defending terrain over conquering it (the peasants actually forcing the Danes into a marsh where several thousand of them drowned). Of course the one massive difference is that the peasants chalked up victory where the Greeks lost (though, yes, getting revenge shortly after at the battle of Salamis must have been satisfying) but, yes, other than that, quite similar.