Battle of Valmy
The song's lyrics reflect the invasion of France by foreign armies (from Prussia and Austria) that was under way when it was written. Strasbourg itself was attacked just a few days later. The invading forces were repulsed from France following their defeat in the Battle of Valmy. As the vast majority of Alsatians did not speak French, a German version ("Auf, Brüder, auf dem Tag entgegen") was published in October 1792 in Colmar.