Julius Caesar, under the banner of the Roman Republic, had since 58 BC invaded Gaul in force, allowing Roman citizens to settle and pacifying the many tribes. Gallic life has been quite disrupted by Caesar's invasion. The Romans allowed no migrations to take place, meaning that the Gauls were forced for the first time in their history to absolutely remain in their territories and deal with whatever problems that arose, namely raids by the Germanic tribes and internal power struggles. This thoroughly alienated the Gauls from the Romans, and in their mutual foe they began to develop national bonds between the tribes, based on their Celtic heritage.