 Complete the following phrase:  In the north, the Austrian siege of Lille had completely failed by 8 October, and Dumouriez now resumed his interrupted scheme for the invasion of the Southern Netherlands. He took commanded of the newly formed Armée de la Belgique  comprising 40,000 soldiers from the Valmy campaign  at Valenciennes on 20 October. Controlling enormously superior forces, ten days later he made his advance to Mons, late in the season and surprising the Austrians. On 6 November, he won the first great victory of the war at 