In September 1775, colonial forces under the command of Philip Schuyler and Richard Montgomery crossed into Quebec with the aim of driving British military forces from Montreal and Quebec City. Guy Carleton, the British governor and military commander, had fortified Fort Saint-Jean as the primary defense of Montreal. The colonial forces, preparing to besiege the fort, sought local support. James Livingston, a grain merchant living near Chambly, about from Saint-Jean, raised a local militia, which in October assisted in the siege and capture of Fort Chambly, and the capture of supplies intended for the besieged moving on the Richelieu River.