In the battle of Valmy the French, under Dumouriez and Kellermann, repulsed the Prussians and their allies, commanded by the Duke of Brunswick. Though not in itself a great victory, its results have led some historians to call that action one of the decisive battles of the world. The final withdrawal of the Prussians, owing to Russian intrigues in Poland, left an open way for the French army into the Austrian Netherlands, which at Jemapes (November 6, 1792) were won for France. Other victories for the Revolution quickly followed, greatly advancing its cause.

After the fall of the Bastille (July 14, 1789), the National Assembly abolished special privileges, slavery, and serfdom in France and all her territories, and decreed equal taxation. A new constitution was made. These acts heightened popular enthusiasm for the revolt. Political clubs, chief of which was that of the Jacobins, were formed in Paris. They were fiercely uncompromising in their demand for the overthrow of the monarchy. Many of the nobles hastened to quit the country. The King was virtually made prisoner in Paris, whence he attempted to escape, but was captured by insurgents and closely guarded in the city.

The National Assembly came to an end and was succeeded (October 1, 1791) by the Legislative Assembly, a still more radical body, which for a year practically ruled France over the head of the King.

Such was the state of affairs in France when, notwithstanding the complications in the East, the Emperor Leopold II and King Frederick William II of Prussia issued the Convention of Pillnitz (August, 1791). This was the basis of an alliance for the rescue of Louis XVI from his enemies, and for his full restoration to power. It led a little later to a formidable coalition of sovereigns against the Revolution. Brunswick advanced toward Paris, but while he hesitated in his progress the French army, under Dumouriez, was increased in numbers and discipline. Dumouriez was on the Belgian border, preparing for his "Argonne campaign," the first events of which no one has better described than Lamartine.

While the interregnum of royalty and republicanism delivered Paris over to the revolutionists, France, with all its frontiers open, had for security nothing but the small forest of Argonnes and the genius of Dumouriez. On September 2, 1792, this general was shut up with sixteen thousand men in the camp of Grandpré, occupying with weak detachments the intermediate defiles between Sedan and Sainte-Menehould, by which the Duke of Brunswick might attempt to break his line and turn his position. He caused the tocsin to be rung in the villages, hoping to excite the enthusiasm of the inhabitants; but the captures of Longwi and Verdun, the understanding between the gentlemen of the country and the émigrés,[36] the hatred of the Revolution, and the disproportionate amounts of the coalesced army, discouraged resistance. Dumouriez, left to himself by the inhabitants, could only rely on his own troops. His sole hope was in forming a junction with Kellermann. If that could be effected behind the forest of Argonne before the troops of the Duke of Brunswick could force the natural rampart, Kellermann and Dumouriez, uniting their troops, would have a body of forty-five thousand soldiers to ninety thousand Prussians, and might then with some hope hazard the fate of France on a battle.

Kellermann, who was worthy to understand and second this grand idea, served without jealousy Dumouriez's design, satisfied with his share of the glory if his country should be saved. He marched to Metz, at the extremity of the Argonne, informing Dumouriez of every step he took. But their superior intelligence was a mystery for the majority of officers and soldiery. Provisions were scarce and bad, the general himself eating black bread. Ministers, deputies, Luckner himself—influenced by his correspondents in the camp—wrote perpetually to Dumouriez to abandon his position and retire to Châlons.

Slight skirmishes with the advanced guard of the Prussians, in which the French were always victorious, gave the troops patience. Miaczinski, Stengel, and Miranda drove back the Prussians at all points. Dumouriez, in his position, deadened the shock of the one hundred thousand men whom the King of Prussia and the Duke of Brunswick collected at the foot of Argonne. Chance nearly lost all.

Overcome by fatigue of body and mind, he had forgotten to reconnoitre with his own eyes, and quite close to him, the defile of Croix-au-Bois, which had been described to him as impracticable for troops, particularly cavalry and artillery. He had placed there, however, a dragoon regiment, two battalions of volunteers, and two pieces of cannon, commanded by a colonel; but in consequence of the recall of the dragoons and the two battalions before the troops ordered to replace them had come up, the defile was for a moment open to the enemy. A great many volunteer spies, whom the émigrés had in the villages of Argonne, hastened to point out this weakness to Clerfayt, the Austrian general, who instantly despatched eight thousand men, under the command of the young Prince de Ligne, who seized on the position.

A few hours afterward, Dumouriez, informed of this reverse, placed General Chazot at the head of two brigades, six squadrons of his best troops, four pieces of cannon, besides the artillery belonging to the battalions, and ordered him to attack the place at the bayonet's point, and recover the position at any sacrifice. Every hour the impatient commander despatched aides-de-camp to Chazot to expedite his march and bring him back information. Twenty-four hours passed away thus in doubt. On the 14th Dumouriez heard the sound of firing on his left, and judged by the noise, which receded, that the Imperialists were in retreat and Chazot had gained the forest. In the evening a note from Chazot informed him that he had forced the intrenchments of the Austrians, in spite of their desperate defence; that eight hundred dead lay in the defile, among whom was the Prince de Ligne.