The French Grand Army is currently in retreat. Protect them well. If the withdrawal proceeds smoothly, they may send support units to assist in your own extraction.

The elite guards of the Grande Armée. They are divided into the Old Guard, Middle Guard, and Young Guard. The Old Guard are the best of the best, Napoleon's personal favorites. The Old and Middle Guard are currently escorting Napoleon's retreat, while the Young Guard is busy clearing the bridges for the withdrawal. Everyone is occupied, but the Emperor has seen fit to assign a small detachment of the Old Guard to you (a very small number). The Guard consists of elite branches including artillery, cavalry, infantry, and engineers. Among them, the Marines of the Guard are performing exceptionally well, fighting alongside the Young Guard to absolutely crush the Sixth Coalition forces.

Does it really take this many nations just to stop France? Allied Powers: Russian Empire, United Kingdom, Austria, Prussia, Sweden, Grand Duchy of Mecklenburg-Schwerin, Kingdom of Württemberg, Kingdom of Saxony.

The temporary unit Guest belongs to, formed by drawing small numbers from various other units. The goal is to buy time for the main force and Napoleon to retreat. Napoleon did show some consideration by assigning a few Old Guard members, but... (Damn it, you expect us to stop those guys with just this many?)