On the night of October 8, Burgoyne began his retreat northward. At Saratoga (Schuylerville), his army was surrounded by the Americans. After a week of siege, Burgoyne surrendered on October 17, 1777, under the terms of the Convention of Saratoga. The American victory at Saratoga proved to be the turning point of the Revolution, encouraging France and other European powers to take up arms against England and aid the American cause.