The contubernium was the smallest organized unit of soldiers in the Roman Army and was composed of eight legionaries, the equivalent of a modern squad. The men within the contubernium were known as contubernales. Ten contubernia were grouped into a centuria. Soldiers of a contubernium shared a tent, and could be rewarded or punished together as a unit.
It was led by a Decanus, the equivalent of a junior non-commissioned officer. They were appointed from within the contubernium and were most likely the longest serving legionary. Their duties would include organising the erection of the marching tent and keeping discipline.
Two auxiliary "servants", comparable to modern support troops, were assigned to each contubernium. They were responsible for the care of the contubernium's pack mule, making sure that the legionaries had water during the march, and often had special skills like blacksmithing or carpentry.