The Neman River was then the border of the Russian Empire with Europe.
On July 7, 1807, the Peace of Tilsit was concluded between Napoleon and the Russian Empire. It represented the great triumph of Bonaparte, and it also created the Duchy of Warsaw, as a Polish state in a vassal relationship with Napoleon. It is especially interesting that Napoleon and the Russian Tsar Alexander I signed this peace on a raft that was arranged for the occasion on the river Nemen, the then border of the Russian Empire towards Europe.
The place Tilzit, next to which the mentioned raft was arranged, gave the name to the widely known type of cheese (tilzit, tilsit or tilsiter), which was produced there. Interestingly, in 1946, the Soviets changed the name of that city to Sovietsk, and that name was not later restored. Today, Sovetsk, ie the former Tilsit, is located on the border of the Russian Federation (Kaliningrad region) and Lithuania, on the Russian side of the border.