The second battle of Altenkirchen (19 September 1796) was actually the final act in a three day long rearguard action in which General Marceau made sure that the Archduke Charles of Austria was unable to interfere with the retreat of General Jourdan and the Army of the Sambre-and-Meuse from the River Lahn to Altenkirchen. On 3 September the Archduke defeated Jourdan at Würzburg. The French were forced to retreat north-west across the foothills of the Vogelsberg, reaching the Lahn on 9 September. On the following day Jourdan was joined by General Marceau with 16,000 troops who had been blockading Mainz, and Jourdan decided to make a stand on the Lahn. He hoped to keep the Archduke in the north long enough to allow General Moreau and the Army of the Rhine-and-Moselle to complete their retreat from Bavaria, and in that at least Jourdan was successful. After stopping at Würzburg for long enough to capture the citadel, the Archduke followed the French north-west, reaching the Lahn on 11 September.
The Archduke convinced Jourdan that he was going to attack the left of the French line, at Wetzlar and Giessen, but the main Austrian attack actually came on the French right, at Limburg. By the end of 15 September Jourdan had concentrated his strongest forces on the left. Grenier was at Giessen, Lefebvre at Wetzlar, Championnet was half way between Wetzlar and Limburg at Weilburg and Bernadotte was at Runkel. Marceau had command of the lower Lahn, from Limburg to the Rhine. His main force was posted at Limburg, while General Castelvert held the line from Diez, through Nassau to the Rhine.
In contrast the main Austrian forces, under the Archduke Charles, were posted at Niederbrechen, five miles east of Limburg. Neu's division was at Kirchberg and Hotze was at Weilmünster (ten miles to the east of the Archduke). Kray and Sztaray had been left opposite Giessen and Wetzlar, with orders to make a noisy demonstration that would convince the French that they were the main force. On 16 September Kray attacked at Giessen, and was repulsed, while the Archduke attacked Limburg. The town itself, on the south bank of the Lahn, fell to the Austrians, but Marceau was able to prevent them from crossing the river.
The French position on the Lahn unravelled from right to left. On the night of 16-17 September General Castelvert, who commanded the French forces between the Rhine and Deiz (just to the west of Limburg), worried that an Austrian breakthrough at Limburg might leave him trapped with his back to the Rhine, withdrew north to Montabauer, and then west to the French bridgehead at Neuwied on the Rhine. This left General Marceau's right flank unguarded, and on the morning of 17 September, partly protected by a heavy fog, he withdrew to Molsberg, eight miles to the north-west.
By the end of 16 September Jourdan had finally realised that the main Austrian attack was coming at Limburg, and he send General Bernadotte west to reinforce Marceau. As Bernadotte approached Limburg instead of finding Marceau's men he ran into the advancing Austrians. Bernadotte realised that if he retreated then the French centre, at Runkel and Weilburg, would be exposed to the Austrians. Despite being badly outnumbered Bernadotte held his ground until midday, by which time the troops at Runkel and Weilburg had begun their retreat. Bernadotte then carried out a fighting retreat, which lasted until eight in the evening. On the night of 17-18 September he stopped at Waldenbach, just over ten miles to the north/ north-east of Limburg.
The French left remained in its positions at Wetzlar and Giessen until the end of the day, but at nightfall Jourdan ordered the left to retreat north-west up the Dill River to Herborn, and then to move west to Hof.
Jourdan decided to concentrate his forces behind the River Wied, at Altenkirchen. The Wied rises close to Dreifelden, ten miles to the south-east of Altenkirchen. It then flows north-west to Ingelbach, where it turns west passing just to the south of Altenkirchen. Three miles to the east the River Nister runs parallel to the upper Wied.
The French left would have to move west from Hof to cross the Nister close to Hachenburg, before following the road from Hachenburg to Altenkirchen, which crosses the gap between the Wied and the Nister. The French centre retreated north from Waldenbach, joining the left to the east of the Nister. Marceau, and the French right, had to move north-west from Molsburg to Freilingen, close to the source of the Wied, then continue north-west to Höchstenbach, five miles to the south-east of Altenkirchen. Depending on the situation they could then continue along either bank of the Wied to rejoin the main army.
The only real fighting on 18 September took place around Molsberg, where Marceau was ordered to fight a delaying action to give the French left time to catch up with the centre, which had already reached Schönberg and Höhn, just to the south of Hof. Marceau achieved this, and remained close to Molsberg for the entire day.
Marceau finally left Molsberg at three in the morning on 19 September, but only to pull back a few miles to Freilingen where Jourdan ordered him to make a stand for long enough for the main army to pass through Altenkirchen. While Marceau was fighting his rearguard action Bernadotte was sent ahead of the main army with a force of cavalry, with orders to secure the road to Altenkirchen and the town itself. Grenier's and Championnet's divisions followed next, and were soon through the town and in Jourdan's preferred position behind the Wied. Lefebvre was posted on the heights in front of Altenkirchen, guarding the main road against Kray, who was advancing slowly along the road from Hachenburg.
When he learnt that the main army had started to pass through Altenkirchen, Marceau began his retreat from Freilingen, but he rather misjudged his timing, and he arrived at the northern edge of the forest of Höchstenbach before Grenier's and Championnet's divisions had completely passed through Altenkirchen. Jourdan ordered Marceau to make a stand at the northern edge of the forest. Marceau led the main body of his division back to support his rear-guard, but while he was scouting out the Austrian positions he was shot and mortally wounded by a Tyrolean rifleman.
Depending on your source one of Jourdan, Bernadotte or Lefebvre took over from Marceau, who was taken to a house in Altenkirchen. Marceau's troops rallied for long enough to prevent the Austrians from interfering with the movement of the rest of the army. Having failed to prevent Jourdan from reuniting his army, the Archduke camped at Freilingen.
On the following day Jourdan continued his retreat. The mortally wounded Marceau was left in Altenkirchen, where he was visited by a number of Austrian officers, amongst them Kray. He died at five in the morning on 21 September, just before the Archduke arrived to pay his respects. On 23 September the Austrians delivered Marceau's body to the French bridgehead at Neuwied, and he was buried within the fortified camp at Coblenz, to the accompaniment of salutes of gunfire from both sides.
The fighting around Altenkirchen effectively ended the campaign. The French retreated further north, to the River Sieg, while the Archduke turned south to deal with Moreau, catching him between the Black Forest and the Rhine winning two further battles, at Emmendingen (19 October 1796) and Schliengen (24 October 1796). By the end of the year the French were back where they had started in June.