Contubernium
From Oberon_wiki
A 'Contubernium' (plural: 'Contubernia') is the smallest organised unit within an Imperial Army Legion. It composes of 8 men, all Legionaries, one of who usually has the rank of 2nd or 1st 'Legionary'. Two Contubernia are often combined to form a unit, and they are then led by a single 'Decurian' (a junior officer).
Typically 10 Contubernia form 'Centuries' which are led by one (or, more commonly, two) 'Centurians' (a senior officer).
