the century - fighting unit

[Sean Manning]

For a similar example of how military terminology can get seperated from the original meaning, an Athenian trireme had an officer called a pentekontarchon ("fifty-leader") who doesn't seem to have commanded 50 of anything. They figure the post was originally something like "captain of a pentekonter" and when Athens adopted triremes they kept the name and changed the duties. Or we still have Lieutenants and Lieutenant Colonels, even though they aren't anyone's deputy (the original meaning) any more.