Gallia Comata (Latin:long-haired Gaul ), in Roman antiquity also Tres Galliae (three Gauls), the land of Gaul comprising the three provinces (1) Aquitaine, west of Bay of Biscay and bordered on the south by the Pyrenees; (2) Celtica (or Gallia Lugdunensis) with Lugdunum (Lyon) as its capital on the eastern frontier of Gaul and northwest to Brittany; and (3) Belgica (or Gallia Belgica) in the north, where Trier and Reims were the capitals and many of the people were of Germanic origin. The only garrison was a single cohort in Lugdunum guarding the Imperial Mint, but the army of the Rhine could and could quickly move into Gallia Comata in case of trouble.
A fourth Roman province, Narbonensis lay between them and the Mediterranean Sea. It was governed by a Senate-appointed proconsul, while each of the Tres Galliae was governed by an imperial legate of Praetorian stature.