During the 1st and 2nd centuries AD, the seven western cities of Gallia Belgica (Morins, Atrebates, Ambiens, Viromanduens, Bellovaques, Sulbanectes and Suessions) show a dense network of small towns, ten of which are « true » towns (in addition to capital towns). Between the end of the 3rd century and the beginning of the 5th century, urbanization greatly decreases, but some small towns still exist. This paper examines how major small towns which grow during the 1st and 2nd centuries AD changed or disappeared during Late Antiquity.