Strategos, plural strategoi, Latinized strategus, (; Doric Greek: στραταγός, stratagos; meaning "army leader") is used in Greek to mean military general. In the Hellenistic world and the Eastern Roman Empire the term was also used to describe a military governor. In the modern Hellenic Army, it is the highest officer rank. Etymology Strategos is a compound of two Greek words: stratos and agos. Stratos (στρατός) means "army", literally "that which is spread out", coming from the proto-Indo-European root *stere- "to spread". Agos (ἀγός) means "leader", from agein (ἄγειν) "to lead", from the proto-Ιndo-Εuropean root *ag- "to drive, draw out or forth, move”. Classical Greece Athens In its most famous attestation, in Classical Athens, the office of strategos existed already in the 6th century BC, but it was only with the reforms of Cleisthenes in 501 BC that it assumed its most recognizable form: Cleisthenes instituted a board of ten strategoi who were elected annually, one from each tribe (phyle). The ten were of equal status, and replaced the polemarchos, who had hitherto been the senior military commander. At the Battle of Marathon in 490 BC (according to Herodotus) they decided strategy by majority vote, and each held the presidency in daily rotation. At this date the polemarchos had a casting vote, and one view among modern scholars is that he was the commander-in-chief; but from 486 onwards the polemarchos, like the other archontes, was appointed by lot. The annual election of the strategoi was held in the spring, and their term of office coincided with the ordinary Athenian year, from midsummer to midsummer. If a strategos died or was dismissed from office, a by-election might be held to replace him. The strict adherence to the principle of a strategos from each tribe lasted until , after which two strategoi could be selected from the same tribe and another tribe be left without its own strategos, perhaps because no suitable candidate might be available. This system continued at least until , but by the time Aristotle wrote his Constitution of the Athenians in , the appointments were made without any reference to tribal affiliation. Hence, during the Hellenistic period, although the number of the tribes was increased, the number of strategoi remained constant at ten. In the early part of the 5th century, several strategoi combined their military office with a political role, with Themistocles, Aristides, Cimon, or Pericles among the