After forcing the surrender of the Brunswickian army, Napoleon swiftly led his forces towards their next target. Currently, they were stationed in Longwy, facing the Austrian army commanded by Archduke Karl.
Throughout this war, Austria's primary focus had always been Italy. Consequently, the majority of their forces were deployed to the Italian theater of war. Even after the Russo-Prussian coalition's defeat in Italy and Russia's subsequent betrayal, Austria remained committed to the Italian front. Especially when Napoleon, leading the main forces of the French army in Italy, returned to France to confront the British, Austria immediately shifted most of its resources towards Italy.
Despite the departure of the Russian coalition, only a few French troops remained in Italy, mostly Italian auxiliaries. The Austrians believed these would be easy targets since the French had shifted most of their military production capabilities to support the northern front. Joseph's style of warfare was indeed resource-intensive. It was rumored that Napoleon once commented on military commanders of the past and present, saying, "What does Joseph know about fighting? He only knows how to fight with money!"
At first, the Italians had won a few impressive battles, but as their supplies dwindled, their combat effectiveness sharply declined. They quickly found themselves on equal footing with the better-supplied Austrians, gradually losing ground.
Consequently, the Emperor had urgently written to Archduke Karl, requesting additional supplies. Still, he delayed sending all those letters and instead rerouted the supplies and troops to Italy. If it wasn't for the fact that replacing Archduke Karl would be an insult to the Habsburgs, the Emperor might have considered detaining him and redirecting his forces to Italy.
Thus, Archduke Karl's army was neither elite nor well-supplied, putting them at a disadvantage. Archduke Karl was aware of his army's condition and, in previous battles, avoided engaging in direct combat, instead trailing behind the British and Prussians to seize territory and gain advantages.
When the Anglo-Prussian coalition became trapped at Verdun, they had initially requested Archduke Karl's reinforcements. However, Archduke Karl, sensing something amiss from Brunswick's messages, offered various excuses to delay his march to Verdun. It was only after Napoleon sent a letter urging surrender to Brunswick that Archduke Karl finally arrived in Longwy.
Archduke Karl's reconnaissance cavalry ranged far and wide, even keeping an eye on the Verdun area. So, when Napoleon decisively defeated the Anglo-Prussian coalition at Verdun and wiped out their main forces, Archduke Karl received this news rather quickly.
Now, Archduke Karl understood that after the coalition's defeat under Brunswick, his army would surely become a thorn in Napoleon's side. If he didn't eliminate this army, Napoleon, whether heading for Hanover or Austria, would find his army positioned to threaten his flank.
Archduke Karl was now facing a critical choice—retreat immediately, withdraw from Longwy, and clear the path for Napoleon towards Hanover and Berlin. Or, fall back to Luxembourg, using its easily defensible terrain to delay Napoleon and gain time for the allied forces to react, or at least, to initiate peace negotiations.
"After the Battle of Verdun, the French have effectively won this war. The only question left is how this war will conclude. If the French easily conquer Hanover or crush Prussia, Austria will be in grave danger. At that point, even if we wish to negotiate with the French, we won't get favorable terms. So, even if we aim for negotiations, we must be the first nation to reach a peaceful agreement with the French. To achieve that, I intend to immediately retreat to Luxembourg. What are your thoughts on this?" Archduke Karl asked General Nostitz.
Luxembourg was a crucial location, sitting on the path from France to the German states. Its complex geography and natural defenses made it a formidable position. Over the centuries, it had been a hotly contested area, earning nicknames like the "Land of a Thousand Castles" and the "Gibraltar of the North."
Previously, the French had briefly controlled this region, but due to a series of failures by the Northern Army, it had been abandoned. The British and Prussian forces were temporarily occupied elsewhere, allowing the Austrians to seize this strategic location.
Occupying Luxembourg and forcing the French to offer more favorable terms for Austria's withdrawal from the war was the reason Archduke Karl had brought his main force near Verdun after sensing something amiss from Brunswick's messages.
Archduke Karl had barely formed his troops near Luxembourg when General Brissot arrived with a few hundred cavalry. From General Brissot, Archduke Karl gained a deeper understanding of the events at Verdun. He kept General Brissot and his subordinate officers for several more days to learn about the French's new defensive techniques.
However, General Brissot couldn't linger here for long. He left several of his officers behind with Archduke Karl before hastily departing.
Three days after General Brissot's departure, French cavalry began appearing near Luxembourg. That afternoon, the vanguard of the French army, led by Davout, reached Luxembourg.
By now, Napoleon's army had swelled to 120,000 strong, including the original elite Italian legions, over 60,000 strong, more than 40,000 battle-hardened French soldiers from the Verdun campaign, and over 10,000 German mercenaries that the British hadn't yet employed. They had all surrendered to the coalition. Considering the shortage of manpower in many areas, especially a lack of people familiar with the German region's terrain and customs, Napoleon inquired if their leader, Barbou, would accept employment under his command, with a ransom as payment for their freedom.
Barbou keenly sensed that this could be his chance to climb the social ladder and agreed immediately. Thus, these mercenaries, who were on the brink of being discarded, became subordinates of Napoleon.
Of course, Napoleon didn't believe these mercenaries would be of great use on the battlefield. He didn't anticipate needing one-time-use troops like the British did. These mercenaries were mostly dispersed for scouting and similar purposes. This also allowed them to receive some education in revolutionary ideals while with the French army.
"If we want to secure a foothold in the German region, we must implement the same land revolution policies we executed in Italy," Napoleon instructed Joseph before leaving Verdun. He believed that German-speaking mercenaries could be useful at this time.
Initially, Napoleon thought that Archduke Karl would make way for his army, retreating towards Kaiserslautern. In that case, Napoleon planned to leave a diversionary force in Luxembourg while moving the main army toward Prussia. Seizing the opportunity while Prussia was still reeling from its recent defeat, he intended to crush Prussia.
To his surprise, Archduke Karl was resolute and positioned his army in Luxembourg, causing trouble for Napoleon.
Napoleon was confident of defeating Archduke Karl. His army was larger, better equipped, more motivated, better trained, and far more advanced. Archduke Karl had only about 60,000 troops, mainly raw recruits, with few cavalry. Their equipment was relatively outdated—over half their rifles were still muzzleloaders. Moreover, they lacked sufficient artillery.
Given this disparity in forces, Napoleon believed he could overcome Archduke Karl, even if he held the formidable position of Luxembourg. However, he acknowledged that capturing Luxembourg, with its advantageous terrain and fortifications, would still consume considerable time.
Furthermore, Napoleon faced logistical supply issues. This was primarily due to the excessive expenditure of ammunition by Joseph during the Verdun battle, resulting in a severe shortage. The siege warfare ahead would further deplete ammunition stores. Although French arms factories were operating around the clock, they struggled to keep up with the war's demand. Waiting for these supplies to be produced and transported would allow Prussia to raise a large army.
Just as Napoleon was grappling with these concerns, someone arrived with news that the Austrians had sent an envoy.