58-51 B.C., Julius Caesar's campaigns in Gaul. He repulsed the Helvetii as they crossed the Alps, pursued them to Bifracte where he defeated them; routed the Gen. Ariovistus; 57 B.C. he subdued Belgica; attacked the leaders of an anti-Rome conspiracy, the Veneti, defeating them by building his own boats to meet their fleet in the Gulg of Morbihan, Brittany; 55 B.C. repelled a Germanic invasion and crossed the Rhine by building a bridge near Cologne; 54 B.C. invaded Britain put down Belgian revolt, executed one of his most brilliant exploits by crossing the Alps in winter and crushing a widespread revolt in Gaul. Through these wars, Julius Caesar conquered a vast territory by swift military tactics and brilliant organization.