Caesar was still in Rome when news of the revolt reached him. He rushed north in an attempt to prevent the revolt from spreading, heading first to Provence to see to its defense, and then to Agedincum to counter the Gallic forces. Caesar took a winding route to the Gallic army to capture several "oppidium" for food. Vercingetorix was forced to withdraw from his siege of the Boii (allied to Rome) capital of Gorgobina. However, it was still winter, and he realized the reason Caesar had detoured was that the Romans were low on supplies. Thus, Vercingetorix set out a strategy to starve the Romans. He avoided attacking them outright and raided foraging parties and supply trains instead. Vercingetorix abandoned a great many "oppidum", seeking only to defend the strongest, and to ensure the others and their supplies could not fall into Roman hands. Once again, a lack of supplies forced Caesar's hand, and he sieged the "oppidum" of Avaricum where Vercingetorix had sought refuge.