Hesse-Cassel after the Battles of Jena and Auerstedt,
autumn 1806 [*]
Hesse-Cassel . . . was entirely in sympathy with Prussia, and, what was worse in Napoleon’s eyes, with England, who had so often made use of Hessian troops. The Elector [Wilhelm I (1743–1821)] was only restrained from openly joining Prussia by his uncertainty as to the result of the war [between France and Prussia], and his conviction that, if he joined Prussia in a losing fight, Napoleon would inevitably annex his territory. 
He decided to play the dangerous game of sitting on the fence, sitting not evenly, but with the leg on the Prussian side almost on the ground. Napoleon had sent him a distinct warning of the dangers of his position, through the Prince Primate, to whom he wrote on the 1st October: “If the Prince of Cassel is sincere and wishes to remain really neutral, I have no intention of preventing his doing so.” The Emperor went on to say that his troops should not pass through Hessian territory, that he had no ill-will against the Elector, and would not attack him willingly. It was impossible not to read between the lines the scarcely veiled threat, in case the Elector should assume a position of neutrality benevolent to Prussia and malevolent to the French.
That prince, nevertheless, continued to behave towards Prussia rather as an ally than as a neutral. Prussian troops were permitted to pass through his territories, and the friendly demonstrations with which they were received were in no way condemned or discouraged by the Government. To Napoleon’s warning no answer was returned, but the ambassador of Hesse-Cassel was recalled from Paris. The mobilisation of troops was actively pressed, and, so late as a few days before the decisive contest, the Elector was with the King of Prussia, almost on the point of throwing in his lot with that sovereign.
Naturally, when the crushing defeats of Jena and Auerstedt had made manifest the hopelessness of the Prussian cause, the Elector saw fit to disarm, to assume an attitude of genuine neutrality, and to endeavour to appear as if that had been his position all through.
Whether Napoleon ever intended to keep his promise of respecting Hessian neutrality may be left in doubt; he was now quite determined to wreak his vengeance on the prince who had so clearly favoured Prussia as far as was possible without actively joining her in the field. The Emperor had decided on annexation, and the dethronement of the Elector.
For this purpose Louis and [Edouard Adolphe Casimir Joseph] Mortier [1768–1835] received instructions to converge so as to meet on the same date at Cassel. The Elector was to be deceived with fair words until the last moment, when the two corps were ready to enter his capital. Mortier was furnished with a formal note detailing the Emperor’s complaints against the court of Cassel, and announcing his intention of annexing the state, and deposing the reigning family. This was to be delivered by an aide de-camp, only the night before the entry of the troops into Cassel. A proclamation of the annexation was also enclosed. This was on the 23rd October.
When Mortier acknowledged this despatch on the 26th he was at Brukenau, a day’s march south of Fulda. His force was by no means so strong as Napoleon had expected. The two Italian regiments not having arrived, he had but three regiments of French light infantry, in all not more than 5500 strong. On the night of the 31st October, Mortier on the south and the advance guard of Louis on the north, were each within a short march of Cassel. The former reported that no suspicions of his real intentions had been aroused, and that he was believed to be marching through Cassel to occupy Hanover. He now despatched his aide-de-camp with the Emperor’s note.
At 3 A.m. the Hessian ministers came with the submission of the Elector, for whom and the Hereditary Prince [Wilhelm II (1777–1847)] they asked a passport to the Emperor’s headquarters. This being refused, the two princes left Cassel and succeeded, after narrowly escaping some French troops, in getting away towards the north. Next morning [1 November 1806], Cassel was occupied without resistance by Mortier, who was joined there by Louis’s troops. The Hessian troops there were disarmed and disbanded. A few days later Hanau was occupied peaceably, and the rest of the Hessian troops were disarmed.
The corps of Louis and Mortier were now available for the conquest of Hanover. For the moment Mortier was placed under the nominal command of Louis, who was required to give him a corps of about 12,000 men, with which to occupy Hanover and Hamburg. Louis, on the plea of ill-health, was allowed, on the 9th November, to retire to his kingdom, leaving Mortier in command.
French troops began to appear before Hameln on the 7th November; on the 10th part of Mortier’s corps arrived. The place had, since its surrender by the French in March 1806, been placed in a good state of defence; its works were strong; it was amply provisioned, and Lecoq occupied it with about 10,000 men.
When Mortier proceeded to Hanover and Hamburg he left but 6000 men, under Dumonçeau, to blockade the fortress with its garrison nearly twice as strong.
It seems unnecessary to go into any detail of this blockade, which was of very little interest
About this time, Napoleon had concluded with Luchesini, the envoy of the King of Prussia, an armistice, on terms very hard towards the latter, amongst which was a provision for the surrender of the remaining Prussian fortresses. Napoleon, pretending to believe in the immediate ratification of this agreement (which was, as a matter of fact, refused by the King), despatched Savary to Hameln to see what he could effect by means of diplomacy.
Savary, arriving before Hameln on the 19th November, immediately entered into negotiations with Lecoq and the other Prussian generals. After pointing out to them the hopelessness of their position, with no Prussian force to come to their assistance within 250 miles, he clinched the matter by explaining the agreement with Luchesini. Lecoq decided to surrender next day. That he must eventually surrender was certain, but he was equally certainly wrong not to hold out to the last, thereby detaining a substantial portion of Napoleon’s army, every man of which was required for the prosecution of the campaign in Poland, Silesia, and Pomerania.
When the terms of the capitulation, which were similar to those of Prenzlau, became known to the Prussian troops, they broke into open mutiny; discipline was at an end; the wine-shops were broken open; crowds of drunken troops paraded the streets, robbing, and even firing upon one another and the inhabitants. Even the officers broke out, demanding orders for their pay on the treasuries of the provinces occupied by the French, and for the soldiers permission to retire to their homes, instead of being treated as prisoners of war.
Savary took strong measures to enforce the capitulation. His cavalry entered Hameln, driving the Prussian troops through the place on to the plain outside, where they were surrounded and disarmed.
Leaving Dumonçeau at Hameln, Savary went on to the little fortress of Nieuburg, before which also a blockading force had been left. The fortress surrendered on the 25th November. Mortier occupied Hanover on the 12th November without opposition. Plassenberg, a small fort near Hof, which had been blockaded by a few Bavarians, surrendered on the 25th November, without a shot being fired.
[*] Francis Loraine Petre, Napoleon’s Conquest of Prussia 1806 (London 1907), 294–99. The map includes towns mentioned in the narrative as well as Göttingen, where Caroline was born and grew up: Ignaz Heymann, PostKarte von Deutschland und den angrenzenden Laendern, 2nd ed. (Triest 1806); Bibliothèque nationale de France, département Cartes et plans..
 Napoleon did; after the Treaty of Tilsit in 1807, most of Hesse-Cassel was incorporated into the newly formed Kingdom of Westfalia. Back.
Translation © 2018 Doug Stott