in the army and air force, these names are often based on the unit or post that a holder of each rank usual commands. for example, a "tagmatarchis" is in charge of a "tagma", which is derived from an ancient greek word translateable as "command", "order", or "class", and in modern greek is a unit equivalent to a battalion in other armies; hence a modern "tagmatarchis" is a rank equivalent to major in other armies. similarly, a "lochagos" normally commands a "lochos" (a word that originally meant "warband") , which in ancient greece was a 100-strong hoplite unit, but in modern greek usage is equivalent to an infantry company. hence a "lochagos" is the equivalent of a captain in other armies, and the modern greek equivalent of an army first lieutenant is the modern neologism "ypolochagos": literally, "sub-captain". likewise, the modern greek equivalent of a sergeant is a "lochias".