the most famous war-dance of antiquity, received its name from Pyrrichos, a Dorian. It was danced to the flute, and its time was very quick. Julius Caesar introduced it into Rome. The Romaika, still danced in Greece, is a relic of the ancient Pyrrhic dance.
Ye have the Pyrrhic dance as often, Where is the Pyrrhic phalanx gone?
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894