Due to the poor harvest and insufficient supplies, Caesar had to disperse his eight legions over a very vast area of Gaul during the winter. This would reduce transportation consumption and allow better access to food from nearby tribes.
However, this led to the Roman Army being spread thin and somewhat vulnerable.
The Gaul tribes in the Belgium region had only recently allied with Rome. Caesar did not trust them, so he not only stationed a considerable number of troops there but also interfered with the appointment of tribal leaders, causing some tribal nobles to harbor resentment.
After Caesar stationed his troops separately, they saw the opportunity to resist the Romans and secretly contacted several tribes to launch an independent revolt simultaneously.
