After the declaration of war by France to the Austrian Archduke Francis II on April 20, 1792, counter-revolutionaries in Mainz gathered in July promising to defeat the French revolutionaries and carrying out an "infliction of exemplary punishment."

But the failure of the escape of Louis XVI to Varenne lead to the arrest and indictment of the king of France.

The French troops, now called "Army of the Vosges" by decision of the convention, began the encirclement and siege of the city on October 18.

"On the 19th, the army corps arrived in sight of Mainz and surrounded the place; our right was based in the village of Hechtsheim, on our left the Rhine; we occupied Bretzenheim, Zahlbach, the mill and the heights of Gonsenheim and head of Mombach woods; headquarters was established at Marienborn.

One of our columns from this village Zahlbach, marched to within cannon shot of the town; the troops of Mainz, who lined the advanced works, fired and wounded few men.

This operation complete, the howitzer batteries opened fire on the fort Hauptstein and the body of the place; but they were only field guns, and as the fortifications that surround the main forum for Mainz are very extensive, we quickly recognized the impossibility to wear down the city using six inch shells.

The engineer commander Clémencey proposed to use red balls; Custine but laughed and said he would have the city without resorting to fire.

In addition, General Custine, who was housed at the Castle of the Prince Electors, provided all kinds of instructions for the protection of the university and the premises of the arch-bishop.

Here's what one of the Germans said, who liked the arrival of the French: "Finally, our people began to reject their chains and gain human dignity.