The storm of the lines of Wissembourg (12-13 October 1793) was an Allied victory on the Rhine front late in 1793 that briefly threatened the entire French position in Alsace. At the end of the siege of Mainz (14 April-23 July 1793) the French were holding a line that ran west from Lauterbourg on the Rhine to Saarbrucken. The western part of this line, from Lauterbourg to Wissembourg (Weissenburg in German), was protected by the Lines of Wissembourg, a series of fortifications built nearly a century earlier to protect Alsace from invasion along the flat plain between the Vosges and the Rhine. The Army of the Rhine defended the Lines, the Army of the Rhine was at Saarbrucken and the Corps of the Vosges linked the two, with camps at Hornbach and Kettrick.
After the siege of Mainz the Prussians and Austrians advanced slowly down towards the French lines. By mid September the Austrians under General Würmser had begin to probe at the lines, but the Prussians, under the Duke of Brunswick (but with the king of Prussia present), were at Kaiserslautern, some to the north, with a strong force posted further south at Pirmasens
On 14 September the French had attacked the Prussian position at Pirmasen and had suffered a heavy defeat. In the aftermath of this defeat the Corps of the Vosge had been forced to retreat from its camp at Hornbach (just north of the current German border) to a point south of Bitche (nine miles to the south). The nearest part of the Army of the Moselle was at Sarreguemines, fifteen miles to the west. There was thus a gap between the right wing of the Army of the Moselle and the left wing of the Army of the Rhine.
The Allies decided to take advantage of this to force the French to abandon the Lines of Wissembourg. Würmser's Austrians were to launch a series of frontal assaults on the Lines, while the Prussians marched around the French left, passing through Bitche before emerging to the south west of Wissembourg.
The Prussian march began on the night of 12-13 September, while the Austrian attacks began early on the morning of 13 September. The attacks on the French right, around Lauterbourg, were repulsed, but on the left the French were forced out of Wissembourg. They then took up a new position at the Geisberg, just to the south of the town, and prepared to defend this new line, but at this point news reached them of the Prussian advance, and the French were forced to retreat back to Haguenau, half way to Strasbourg.
The attack on the lines of Wissenbourg had been a very costly success - the French suffered 2,000 casualties, the Allies around 4,000. Worse was to follow. Rather than take advance to their success to invade Alsace or Lorraine, the Austrians and Prussians once again fell out. Although Würmser advanced towards Strasbourg, the Prussians concentrated on besieging a number of minor French posts in the Vosges, before retreating at the first sign of a French counterattack. By the end of the year the Austrians had pulled back across the Rhine.