A polemarch (/ˈɔːləˌmɑrk/, from Ancient Greek: πολέμαρχος, polemarchos) was a senior military title in various ancient Greek city states (poleis). The title is composed out of the polemos (war) and archon (ruler/leader) and translates as "warleader" or "warlord", one of the nine archontes (ἄρχοντες) appointed annually in Athens. The name indicates that the polemarchos' original function was to command the army; presumably the office was created to take over this function from the king. Eventually military command was transferred to the strategoi (στρατηγοί), but the date and stages of the transfer are not clear. At Marathon in 490 BC the strategoi debated and voted on strategy, but Callimachus the polemarch had a casting vote, and he was the leader; it is disputed whether that means he was the real, or merely the titular commander-in-chief. Certainly the polemarchos no longer had military authority after 487/486 BC, when archontes were appointed by lot and it could not be expected that every polemarch would make a competent commander.

A polemarch (/ˈɔːləˌmɑrk/, from Ancient Greek: πολέμαρχος, polemarchos) was a senior military title in various ancient Greek city states (poleis). The title is composed out of the polemos (war) and archon (ruler/leader) and translates as "warleader" or "warlord", one of the nine archontes (ἄρχοντες) appointed annually in Athens. The name indicates that the polemarchos' original function was to command the army; presumably the office was created to take over this function from the king. Eventually military command was transferred to the strategoi (στρατηγοί), but the date and stages of the transfer are not clear. At Marathon in 490 BC the strategoi debated and voted on strategy, but Callimachus the polemarch had a casting vote, and he was the leader; it is disputed whether that means he was the real, or merely the titular commander-in-chief. Certainly the polemarchos no longer had military authority after 487/486 BC, when archontes were appointed by lot and it could not be expected that every polemarch would make a competent commander.

There were ten generals (strategos) - one from each tribe commanding their tribal contingent. The nominal war leader was the Polemarch Callimachus. The story is that, as they waited for an opportunity to attack, each of the ten took it in turns day about to be commander. On the tenth day when the battle was actually joined, it was the turn of Miltiades.