during the gallic war, julius caesar ended the germanic presence in alsace by destroying ariovistus. he built a bridge across the rhine in 55 bc and entered germania. he convinced the suebi and other tribes not to interfere in gaul, which was roman territory. other than venturing into germania a second time in 53 bc and warring against several tribes, he left germania alone. this established the rhine as the boundary between germania and roman gaul. from 49–45 bc, caesar was occupied by the civil war. he was then assassinated in 44 bc.