The Allies needed a base for provisions and a good river crossing. On 2 July, therefore, Marlborough stormed the fortress of Schellenberg on the heights above the town of Donauwörth. Count Jean d'Arco had been sent with 12,000 men from the Franco-Bavarian camp to hold the town and grassy hill but after a fierce battle, with heavy casualties on both sides, Schellenberg fell. This forced Donauwörth to surrender shortly afterwards. Maximilian, knowing his position at Dillingen was now not tenable, took up a position behind the strong fortifications of Augsburg.