Kingdom of Prussia re-conquers Mainz from France.

The Kingdom of Prussia was a German state that existed from 1701 to 1918. It played a significant role in the unification of Germany in 1871 and was a major constituent of the German Empire until its dissolution in 1918. Although it took its name from the region called Prussia, it was based in the Margraviate of Brandenburg. Its capital was Berlin.

Mainz is the capital and largest city of the German state of Rhineland-Palatinate, and with around 223,000 inhabitants, it is Germany's 35th-largest city. It lies in the Rhine-Main Metropolitan Region—Germany's second-largest metropolitan region after Rhine-Ruhr—which also encompasses the cities of Frankfurt am Main, Wiesbaden, Darmstadt, Offenbach am Main, and Hanau.