The British siege of Fort Niagara in July 1759 was part of a campaign to remove French control of the Great Lakes and Ohio Valley regions, making possible a western invasion of the French province of Canada in conjunction with General James Wolfe's invasion to the east.

The forces left to defend Niagara consisted of about 200 men from the regiments of Royal Roussillon, Languedoc, La Sarre, and Béarn, 20 artillerymen, and about 300 provincial troops and militia.

Delayed by high water on the Mohawk River and the late arrival of some of the provincial companies, the expedition did not begin leaving Schenectady until mid-May.

Prideaux was killed when a shell fragment from one of his own guns hit him, and command of the British forces fell to Sir William Johnson.

In the same month, Montcalm led the defences against British General James Wolfe in the three-month siege of Quebec City.

The signing of the Articles of Capitulation saw the end of major combat operations in the North American theatre of the Seven Years' War.