When Julius Caesar invaded the country, some fifty years before the birth of Christ, he found it divided into three principal parts: there was Aquitaine, the land of springs and waters, extending, in the southwest, from the ocean to the Garonne, already a land of pleasant life, rich in commerce and refinement; there was Celtic Gaul, the west, which reached from the Atlantic to the Marne and the Seine; and there was Belgian Gaul (as Caesar calls it), that north-eastern space between the Seine and the Rhine: an expanse which roughly corresponds to the provinces devastated by the Great War…