It was the 1st of April; he promised an answer on the 15th. In the interval he threw up forts, dug trenches, and raised walls at every point where a passage could be attempted; and when the time was expired, he declined to permit them to enter the Province. They tried to ford; they tried boats; but at every point they were driven back. It remained for them to go by the Pas de l'Ecluse. For this route they required the consent of the Sequani; and, however willing the Sequani might be to see them in their neighbors' territories, they might object to the presence in their own of such a flight of devouring locusts. Evidently, however, there was some general scheme, of which the entry of the Helvetii into Gaul was the essential part; and through the mediation of Dumnorix, an Aeduan and an ardent patriot, the Sequani were induced to agree. The Province had been saved, but the exodus of the enormous multitude could no longer be prevented. If such waves of population were allowed to wander at pleasure, it was inevitable that sooner or later they would overflow the borders of the Empire. Caesar determined to show, at once and peremptorily, that these movements would not be permitted without the Romans' consent. Leaving Labienus to guard the forts on the Rhone, he hurried back to Italy, gathered up his three legions at Aquileia, raised two more at Turin with extreme rapidity, and returned with them by the shortest route over the Mont Genèvre. The mountain tribes attacked him, but could not even delay his march. In seven days he had surmounted the passes, and was again with Labienus.