After the formation of the Kingdom of Westphalia the infantry regiments continued to wear the old uniform of Hessen-Kassel. However, Napoleon planned to make the newly formed state as a model for other German states. That is why the old uniform was replaced by a new one very quickly.
To 1812 there were eight regiments in the line infantry. Light infantry regiments were formed less, only 4.
The fourth light infantry regiment did not take part in the Russian campaign and fought only at Leipzig.
The main feature of the infantry regiments was the jagers- Carabineers’ battalion created from foresters’ children. This elite part wasn’t in the composition of the guard, but operated as a part of the Guards Infantry Brigade. The soldiers of the battalion were armed with threaded nipples.