The natural reaction against a cause which looked for foreign aid gave a new strength for the moment to William in England; but ill luck still hung around the Grand Alliance. So urgent was the need for his presence abroad that William left as we have seen his work in Ireland undone, and crossed in the spring of 1691 to Flanders. It was the first time since the days of Henry the Eighth that an English king had appeared on the Continent at the head of an English army. But the slowness of the allies again baffled William's hopes. He was forced to look on with a small army while a hundred thousand Frenchmen closed suddenly around Mons, the strongest fortress of the Netherlands, and made themselves masters of it in the presence of Lewis. The humiliation was great, and for the moment all trust in William's fortune faded away. In England the blow was felt more heavily than elsewhere. The Jacobite hopes which had been crushed by the indignation at Tourville's descent woke up to a fresh life. Leading Tories, such as Lord Clarendon and Lord Dartmouth, opened communications with James; and some of the leading Whigs with the Earl of Shrewsbury at their head, angered at what they regarded as William's ingratitude, followed them in their course. In Lord Marlborough's mind the state of affairs raised hopes of a double treason. His design was to bring about a revolt which would drive William from the throne without replacing James on it, a revolt which would in fact give the crown to his daughter Anne whose affection for Marlborough's wife would place the real government of England in Churchill's hands. A yet greater danger lay in the treason of Admiral Russell who had succeeded Torrington in command of the fleet. [Sidenote: Battle of La Hogue.]