By the plan of this summer’s campaign, Canada was to be assailed on three sides at once. Upon the west, General Prideaux was to attack Niagara; upon the south, General Amherst was to advance upon Ticonderoga and Crown Point; while upon the east, General Wolfe was to besiege Quebec; and each of these armies, having accomplished its particular object, was directed to push forward, if possible, until all three had united in the heart of Canada. In pursuance of the plan, General Prideaux moved up Lake Ontario and invested Niagara. This post was one of the greatest importance. Its capture would cut off the French from the whole interior country, and they therefore made every effort to raise the siege. An army of seventeen hundred French and Indians, collected at the distant garrisons of Detroit, Presqu’ Isle, Le Bœuf, and Venango, suddenly appeared before Niagara.[122] Sir William Johnson was now in command of the English, Prideaux having been killed by the bursting of a cohorn. Advancing in order of battle, he met the French, charged, routed, and pursued them for five miles through the woods. This success was soon followed by the surrender of the fort. In the mean time, Sir Jeffrey Amherst had crossed Lake George, and appeared before Ticonderoga; upon which the French blew up their works, and retired down Lake Champlain to Crown Point. Retreating from this position also, on the approach of the English army, they collected all their forces, amounting to little more than three thousand men, at Isle Aux Noix, where they intrenched themselves, and prepared to resist the farther progress of the invaders. The lateness of the season prevented Amherst from carrying out the plan of advancing into Canada, and compelled him to go into winter-quarters at Crown Point. The same cause had withheld Prideaux’s army from descending the St. Lawrence.