In the North American theatre, France was allied with various Native American peoples during the Seven Years' War and, despite a temporary success at the battles of the Great Meadows and Monongahela, French forces were defeated at the disastrous Battle of the Plains of Abraham in Quebec. In Europe, repeated French attempts to overwhelm Hanover failed. In 1762 Russia, France, and Austria were on the verge of crushing Prussia, when the Anglo-Prussian Alliance was saved by the Miracle of the House of Brandenburg. At sea, naval defeats against British fleets at Lagos and Quiberon Bay in 1759 and a crippling blockade forced France to keep its ships in port. Finally peace was concluded in the Treaty of Paris (1763), and France lost its North American empire.