A national anthem is a song praising and representing a certain country, ideology, religion, ethnic group, et cetera.
HistoryThe first known national anthem is attested to be the two (most often the Second) Delphic Hymns to Apollo, in its anthem form only Ode to Apollo (Greek: Ωδή στον Απόλλωνα, O̱dí̱ ston Apóllo̱na), an Ancient Delphic song adopted by the Greek Pagans in order to differentiate themselves from the larger Greek Christian community. Soon afterwards, the first military and national anthem was adopted by the Empire of Mecca, was mostly a mocking tune with mocking tunes of the "decaying and pox-infested" Byzantine and Aramean emperors. It is attested it was adopted during the War of the Trinity and the Religious Crisis of the VIII Century, although most of them delay the anthem adopting until as far as the 1100's.
List of National Anthems
Anthem of the Persian Empire