The Royalist plan of campaign was this: They reckoned the energy of the Revolution so low that they counted pretty confidently, in the summer of 1792, on the ability of their party to defend the Tuileries against any force which could be brought against it; but assuming that the Tuileries could not be defended, and that the King and Queen should be massacred, they believed that their own position would be improved. Their monarchical allies would be thereby violently stimulated. It was determined, therefore, that, regardless of consequences to their friends, the invading army should cross the border into Lorraine and, marching by way of Sierk and Rodemach, occupy Châlons. Their entry into Châlons, which they were confident could not be held against them, because of the feeling throughout the country, was to be the signal for the rising in Vendée and Brittany which should sweep down upon Paris from the rear and make the capital untenable. At Châlons the allies would be but ninety miles from Paris, and then nothing would remain but vengeance, and vengeance the more complete the greater the crime had been.
All went well with them up to Valmy. The German advance on August 11, 1792, reached Rodemach, and on August 19, the bulk of the Prussian army crossed the frontier at Rédagne. On August 20, 1792, Longwy was invested and in three days capitulated. In the camp of the Comte d'Artois "there was not one of us," wrote Las Casas, "who did not see himself, in a fortnight, triumphant, in his own home, surrounded by his humbled and submissive vassals." At length from their bivouacs at Saint-Remy and at Suippes the nobles saw in the distance the towers of Châlons.
The panic at Châlons was so great that orders were given to cut the bridge across the Marne, but it was not until about September 2, that the whole peril was understood at Paris. It is true that for several weeks the government had been aware that the West was agitated and that Rouërie was probably conspiring among the Royalists and nonjuring priests, but they did not appreciate the imminence of the danger. On September 3, at latest, Danton certainly heard the details of the plot from a spy, and it was then, while others quailed, that he incited Paris to audacity. This was Danton's culmination.
As we look back, the weakness of the Germans seems to have been psychological rather than physical. At Valmy the numbers engaged were not unequal, and while the French were, for the most part, raw and ill-compacted levies, with few trained officers, the German regiments were those renowned battalions of Frederick the Great whose onset, during the Seven Years' War, no adversary had been able to endure. Yet these redoubtable Prussians fell back in confusion without having seriously tried the French position, and their officers, apparently, did not venture to call upon them to charge again. In vain the French gentlemen implored the Prussian King to support them if they alone should storm Kellermann's batteries. Under the advice of the Duke of Brunswick the King decided on retreat. It is said that the Duke had as little heart in the war as Charles Fox, or, possibly, Pitt, or as his own troops. And yet he was so strong that Dumouriez, after his victory, hung back and offered the invaders free passage lest the Germans, if aroused, should turn on him and fight their way to the Marne.
To the emigrants the retreat was terrible. It was a disaster from which, as a compact power, they never recovered. The rising in Vendée temporarily collapsed with the check at Châlons, and they were left literally naked unto their enemy. Some of them returned to their homes, preferring the guillotine to starvation, others, disguised in peasants' blouses, tried to reach Rouërie in La Vendée, some died from hardship, some committed suicide, while the bulk regained Liège and there waited as suppliants for assistance from Vienna. But these unfortunate men, who had entered so gayly upon a conflict whose significance they could not comprehend, had by this time lost more than lands and castles. Many of them had lost wives and children in one of the most frightful butcheries of history, and a butchery for which they themselves were responsible, because it was the inevitable and logical effect of their own intellectual limitations.
When, after the affair of August 10, Danton and his party became masters of the incipient republic, Paris lay between two perils whose relative magnitude no one could measure. If Châlons fell, Vendée would rise, and the Republicans of the West would be massacred. Five months later Vendée did rise, and at Machecoul the patriots were slaughtered amidst nameless atrocities, largely at the instigation of the priests. In March, 1793, one hundred thousand peasants were under arms.
Clearly the West could not be denuded of troops, and yet, if Châlons were to be made good, every available man had to be hurried to Kellermann, and this gigantic effort fell to the lot of a body of young and inexperienced adventurers who formed what could hardly be dignified with the name of an organized administration.
For a long time Marat, with whom Danton had been obliged to coalesce, had been insisting that, if the enemy were to be resisted on the frontier, Paris must first be purged, for Paris swarmed with Royalists wild for revenge, and who were known to be arming. Danton was not yet prepared for extermination. He instituted domiciliary visits. He made about three thousand arrests and seized a quantity of muskets, but he liberated most of those who were under suspicion. The crisis only came with the news, on September 2, of the investment of Verdun, when no one longer could doubt that the net was closing about Paris. Verdun was but three or four days' march from Châlons. When the Duke of Brunswick crossed the Marne and Brittany revolted, the government would have to flee, as Roland proposed, and then the Royalists would burst the gates of the prisons and there would be another Saint Bartholomew.
Toward four o'clock in the afternoon of September 2, 1792, the prison of the Abbaye was forced and the massacres began. They lasted until September 6, and through a circular sent out by Marat they were extended to Lyons, to Reims, and to other cities. About 1600 prisoners were murdered in Paris alone. Hardly any one has ever defended those slaughters. Even Marat called them "disastrous," and yet no one interfered. Neither Danton, nor Roland, nor the Assembly, nor the National Guard, nor the City of Paris, although the two or three hundred ruffians who did the work could have been dispersed by a single company of resolute men, had society so willed it. When Robespierre's time came he fell almost automatically. Though the head of the despotic "Committee of Public Safety," and nominally the most powerful man in France, he was sent to execution like the vilest and most contemptible of criminals by adversaries who would not command a regiment. The inference is that the September massacres, which have ever since been stigmatized as the deepest stain upon the Revolution, were, veritably, due to the Royalists, who made with the Republicans an issue of self-preservation. For this was no common war. In Royalist eyes it was a servile revolt, and was to be treated as servile revolts during the Middle Ages had always been treated. Again and again, with all solemnity, the Royalists had declared that were they to return as conquerors no stone of Paris should be left standing on another, and that the inhabitants should expire in the ashes of their homes on the rack and the wheel.
Though Danton had many and obvious weaknesses he was a good lawyer, and Danton perceived that though he might not have been able to prevent the September massacres, and although they might have been and probably were inevitable under the tension which prevailed, yet that any court, even a political court, would be better than Marat's mob. Some months later he explained his position to the Convention when it was considering the erection of the tribunal which finally sent Danton himself to the scaffold. "Nothing is more difficult than to define a political crime. But, if a simple citizen, for any ordinary crime, receives immediate punishment, if it is so difficult to reach a political crime, is it not necessary that extraordinary laws ... intimidate the rebels and reach the culpable? Here public safety requires strong remedies and terrible measures. I see no compromise between ordinary forms and a revolutionary tribunal. History attests this truth; and since members have dared in this assembly to refer to those bloody days which every good citizen has lamented, I say that, if such a tribunal had then existed, the people who have been so often and so cruelly reproached for them, would never have stained them with blood; I say, and I shall have the assent of all who have watched these movements, that no human power could have checked the outburst of the national vengeance."