Battle of Fort Beauséjour 1755

Beginning June 3, 1755, a British army under Lieutenant-Colonel Robert Monckton staged out of nearby Fort Lawrence, besieged the small French garrison at Fort Beauséjour with the goal of opening the Isthmus of Chignecto to British control. Control of the isthmus was crucial to the French because it was the only gateway between Quebec and Louisbourg during the winter months.^[2] After two weeks of siege, Louis Du Pont Duchambon de Vergor, the fort's commander, capitulated on June 16.
Wiki on the battle here