Despite the British ships blockading New France, Louis-Joseph de Montcalm-Gozon de St. Véran arrived in Quebec on 11 May 1756. He was accompanied by 1,000 French troops. Although Montcalm was commander-in-chief of all the French forces in Canada, Governor Vaudrueil was his superior.
Even before Montcalm's arrival, Vaudrueil had already formulated plans for an attack on Oswego, a strategically important British fort on the south shore of Lake Ontario. From Oswego, the Anglo-American forces could assemble for an invasion of Canada along the St. Lawrence River.
By June, the militia and Native warriors had isolated Oswego, and Montcalm reluctantly agreed to commit his troops to the operation. He led the La Sarre, Béarn, and Guienne regiments as they joined the Canadian militia outside Oswego. Pierre de Riguad Vaudrueil, the Governor's brother, commanded the Canadians.
Montcalm took command of the operation, and, by 10 August, he had positioned his artillery. Surrounded and faced with an assault by French regulars, Canadian militia, and Native warriors, the commander of Fort Oswego surrendered on 11 August 1756. The French seized 1,600 prisoners as well as 121 cannons, several ships, and a vast quantity of ammunition and supplies. While both Montcalm and Vaudrueil claimed credit for the victory, the success at Oswego was due to the combined operations of Canadian militia and French regulars.
The campaign at Oswego, however, revealed the mutual antipathy between the Canadian and the French military establishments. Montcalm and his regulars were openly contemptuous of the Canadian militia and the Troupes de la Marine. Montcalm regarded the militia as undisciplined rabble and refused to recognize the military value of their skills in la petite guerre (guerrilla warfare). The French regulars considered the militia, who were clad in Native buckskins and fought in a most ungentlemanly manner, as little better than "savages." For their part, the Canadians and their Native allies regarded the perfumed and powdered French regulars with suspicion and disdain.