Baron Philippe Friedrich Dietrich was a French scholar and politician. He was most well known as the first mayor of Strasbourg who encouraged Rouget de l'Isle to write various patriotic songs, including the song which became known as "La Marseillaise", first performed in his living room; he was also known as a scientist, author of a mine survey and the development blast furnaces in France, distinguished geologist and chemist, and member of the Academy of Sciences. As mayor of Strasbourg, he accelerated revolutionary reforms throughout the region.

The Army of the Rhine was formed in December 1791, for the purpose of bringing the French Revolution to the German states along the Rhine River. During its first year in action (1792), under command of Adam Philippe Custine, the Army of the Rhine participated in several victories, including Mainz, Frankfurt and Speyer. Subsequently, the army underwent several reorganizations and merged with the Army of the Moselle to form the Army of the Rhine and Moselle on 20 April 1795.