The British strategy was elegant in its simplicity and brutal in its execution. Three armies would converge on Montreal simultaneously, leaving the French no room to retreat. Amherst himself commanded the largest force -- just over 10,000 men advancing eastward from Lake Ontario along the Saint Lawrence River, aiming to cut off any French escape westward to Detroit. William Haviland led 3,500 men northward from Fort Crown Point through Lake Champlain and the Richelieu River, the route most heavily fortified by the French. James Murray brought 4,000 soldiers westward from Quebec along the Saint Lawrence, approaching Montreal from the east. All three columns would close on the island like a tightening noose before winter set in. Against this force of 18,000, the French commander Levis could muster only 3,200 regulars spread across eight battalions, supplemented by Canadian militia and Indigenous allies whose loyalty was rapidly eroding.

Murray's advance from Quebec, which began on July 13, turned out to be less a military campaign than a political one. Setting out with 2,000 men marching along the riverbank and the rest aboard armed vessels, Murray moved slowly upriver, engaging French defenses but finding greater success with diplomacy. He spoke French fluently, and as he advanced through riverside parishes, he distributed gold and silver coins and administered oaths of loyalty to King George II. The French military had spread propaganda warning Canadians of cruel British treatment, but this backfired -- it was actually the French who threatened repercussions against anyone who failed to resist. Town after town submitted. At Sorel on August 21, Murray launched a nighttime assault with 600 grenadiers and light infantry. The French were driven from their defenses, and the Canadians threw down their arms. By the time Murray anchored below Montreal on August 27, some four thousand Canadians along the Saint Lawrence had been disarmed and sworn allegiance to the British crown. The French officer Bourlamaque wrote furiously to Levis that his troops were deserting in large numbers.

Haviland's column faced the toughest obstacles -- the fortified French positions along the Richelieu River at Ile aux Noix, Fort Saint-Jean, and Fort Chambly, defended by some 3,000 men under Bougainville. The key moment came when Colonel John Darby's light infantry and Robert Rogers' Rangers dragged three cannon through forest and swamps to the rear of the French position at Ile aux Noix -- a maneuver the French believed impossible. Rogers' guns opened fire on the French flotilla. The sloop Waggon had her captain killed and crew scattered before drifting ashore into British hands. Other French vessels fled toward Saint-Jean but ran aground in a river bend. The Rangers swam out with their tomahawks, boarded one vessel, and the rest surrendered. Fort Saint-Jean was abandoned and torched by its garrison. At Fort Chambly, the 70-year-old French commander Paul-Louis Dazemard de Lusignan rejected a demand to surrender, but after a twenty-minute bombardment he capitulated with his 71 men. The Richelieu Valley was in British hands.

Amherst's route from Lake Ontario was the longest and most dangerous. After reducing Fort Levis, where Captain Pierre Pouchot held out with 340 men, the British flotilla ran the treacherous Saint Lawrence rapids. On September 4, they reached the worst stretch -- Les Cedres, the Buisson, and the Cascades. Mohawk river men guided the boats through surging water, but the passage was devastating. Forty-six boats were wrecked, eighteen damaged, one row galley grounded, and 84 men drowned. They emerged into Lake Saint-Louis and landed at Ile Perrot, within striking distance of Montreal. Meanwhile, William Johnson and George Croghan had been systematically turning France's Indigenous allies. Around 800 warriors formerly allied with the French were disarmed by Johnson, and roughly a hundred actively joined the British, taking French prisoners and providing intelligence. By the time all three armies converged, Levis had almost no one left to fight with.

Amherst's army landed unopposed at Lachine on September 6 and marched on Montreal. The French garrison was broken -- soldiers deserting, 241 men unfit for duty, officers reduced to pleading rather than commanding. When Bougainville presented the French surrender terms the next morning, Amherst granted most but refused the one that mattered most to the officers: the honours of war. His justification was blunt -- he cited, in the language of his era, "the infamous part the troops of France have acted in exciting the savages to perpetrate the most horrid and unheard of barbarities." Despite protestations that nearly reached mutiny, Levis was overruled by Governor Vaudreuil. The capitulation was signed on September 8, 1760. The terms for ordinary Canadians were generous: the 60,000 to 70,000 French-speaking inhabitants were guaranteed freedom from deportation, protection of property, freedom of religion, and equal treatment in the fur trade. These provisions were later enshrined in the Proclamation of 1763 and the Quebec Act. Thomas Gage became the first British Governor of Montreal. The Treaty of Paris in 1763 made the transfer of sovereignty permanent.