The North German Confederation Treaty (in German Augustbündnis, or Alliance of August) (also called the North German Federation Treaty and the Treaty of 18 August 1866) was the treaty between the Kingdom of Prussia and other northern and central German states that initially created the North German Confederation, which was the forerunner to the German Empire. This treaty, and others that followed in September and October, are often described as the August treaties, although not all of them were concluded in August 1866.