Unlike most of Napoleon's army the Prussian forces returned home mostly unharmed, saved by the Convention of Tauroggen.

In the successive French assault, the regiment was in the thick of the fighting for the entire day, but was beaten back from the village of Bautzen.

During the brief truce that followed the Battle of Bautzen, the First East Prussian Regiment was placed under the command of Duke Carl of Mecklenburg, still within Yorck's Korps.

They saw heavy fighting at the Combat of Goldberg where the East Prussian Infantry were briefly surrounded by French cavalry.

After being rescued by the Mecklenburg-Strelitz Hussars, Mecklenburg personally led a counterattack of the Regiment's 2nd battalion, and buying time for the rest of his brigade to withdraw and reorganize.

[2] During the Battle of Leipzig, the regiment was positioned on the allied right flank, and was ordered forward on the first day of fighting to take the city of Möckern.

The bloody street fighting took a heavy toll on both sides, and the battle hung in the balance until Prussian cavalry charged and secured the field.

For the next three days of the battle, the regiment stayed on the right flank and pushed to try to encircle Napoleon's forces, even helping to secure the village of Leipzig itself.

East Prussian Infantry, and indeed the actions of the entire brigade, Duke Carl was awarded the Iron Cross.

In 1849, the Regiment was briefly stationed in Danzig, but in 1855 it returned to Königsberg to the newly built Kronprinz Defence Barracks.

This is being done today, on the occasion of appointing my son, His Imperial and Royal Highness the Crown Prince, as an honorary member (à la suite) of the regiment.

At the same time, I decree that the regiment shall wear the Guard Eagle without a star on their helmets and adorn their collars and sleeve patches as follows: a.

I have the utmost confidence that the regiment will draw renewed inspiration from this special mark of my royal favor, and will continue to serve me, my house, and the Fatherland with the same loyalty and dedication it has demonstrated throughout its nearly 250-year history."