1) Gaulish garb 2) Roman-era clothing 
The sagum was a garment of note generally worn by members of the Roman military during both the Republic and early Empire. Regarded symbolically as a garment of war by the same tradition which embraced the toga as a garment of peace, it was slightly more practical in any event, consisting of a simple rectangular segment of cloth fastened by a leat...
• (n.) The military cloak of the Roman soldiers.
Cloak.
A woolen cloak worn by the Roman upper classes. To own such an item gave the impression of the wearer being in the height of fashion. 
Sa'gum noun ; plural Saga . [ Latin sagum , sagus ; confer Greek .... Confer Say a kind of serge.] (Rom. Antiq.) The military cloak of the Roman soldiers. 
A sagum was a military cloak worn by Roman soldiers and inferior officers.