During the operations in Champagne the Austrians had begun the siege of Lille, and at the turning of the tide they withdrew across the frontier, and took up a strong position at Jemmapes, in front of Mons, with 13,000 men. Clerfayt, again, was at their head; and when, on November 6, he saw the French army approaching, nearly 40,000 strong, like Nelson in the hour of death he appeared in all his stars and gold lace, that his men, seeing him, might take heart. He was defeated, and the next evening, at the theatre of Mons, Dumouriez was acclaimed by the Flemish patriots. A week later he was at Brussels, and before the end of the month he was master of Belgium. Holland was undefended, and he proposed to conquer it; but Antwerp was already in the power of the French, and his government feared that England would come to the defence of the Dutch. They directed him to march upon Cologne and complete the conquest of the Rhine. By a decree of November 19 the Convention proffered sympathy and succour to every people that struck a blow for freedom; but the cloven hoof of annexation soon appeared, and it was avowed that the war would be carried on, that the financial needs of France might be supplied, at the expense of the populations which the French arms delivered. These things offended the political, if not the moral sense of Dumouriez. He became alienated from the Convention; and as England went to war on the death of the king, there was no consideration of policy protecting Holland. The invasion was undertaken, and immediately failed. The Austrians, under the duke of Coburg, who on that day founded the great fortunes of his house, came back in force, and gave battle at Neerwinden, close to the fields of Landen and of Ramillies. Here, March 18, Clerfayt crushed Dumouriez's left wing, and recovered the Belgic provinces as suddenly as he had lost them four months earlier.