The Treaty of Frankfurt was signed May 10, 1871, at the end of the Franco-Prussian War.

The treaty:

• confirmed the final frontier between France and Germany - involving the cession of most of Alsace and the Lorraine departement of Moselle to Germany.
• set a framework for the withdrawal of German troops from certain areas
• regulated the payment of the French War Indemnity of 5 billion francs
• the acceptance of Wilhelm I of Prussia to be Kaiser of the German Empire
• forced to have military occupations in France until indemnity is paid

It also clarified the following points:

• the use of navigable waterways in connected to Alsace-Lorraine
• trade between the two countries.
• the return of prisoners of war