THE PRE-REVOLUTION ERA 333 British, were in charge of the Hanoverian frontier; the rest Frederick had to look after for himself. The year brought violent alternations of fortune. Frederick, swiftest and most sudden of generals, dashed from Saxony upon Prague and won a great victory; but not long afterwards, excessive confidence led him to disaster at Kolin, and he had to beat a. retreat from Bohemia with shattered forces. The Duke of Cumberland, in command of the army in Hanover, was driven by a French army northwards to Klosterseven, where he was compelled to capitulate under a convention which the indignant British government refused to ratify. But Frederick recovered himself, and at Rosbach inflicted a great defeat on a second French army which was advancing on Saxony. Thence he dashed to the opposite side of the war area, and shattered at Leuthen an Austrian army engaged in subjugating Silesia. The defeat at Rosbach prevented the French from taking advantage of their success in Hanover, where the British and Hanoverian troops were placed under the command Ferdinand of of the skilful Ferdinand of Brunswick, and thence- Brunswick, forth proved themselves fully able to cope with all the forces that were sent against them. But over the whole of the rest of the field, though Frederick might win victories, he could only save himself from destruction by the rapidity of his movements. When he had smitten one army, no long time ever elapsed before he had to dash away with the same troops to meet another army on another quarter. Thus in the next year 1758, while Ferdinand drove the French over the Rhine, Frederick had to drive back the advancing Russians at Zorndorf, Frederick's and then to clear Austrian armies out of both struggle. Silesia and Saxony. In the year following he could not prevent the Austrian s from capturing the Saxon capital, Dresden, and was severely defeated by the Russians at Kunersdorf ; although there was compensation in a great victory won by Ferdinand over the French at Minden. For one, however, of his opponents this year was extremely disastrous. The British general Wolfe succeeded in capturing
