Neman, Ger. Memel, Lithuanian Nemanos, Pol. Niemen, river, c.580 mi (930 km) long, rising in central Belarus, SW of Minsk. It flows generally W to Grodno, then N and W through S Lithuania to form part of the Lithuania-Kaliningrad Region border before entering the Kursky Zaliv of the Baltic Sea through a small delta. Kaunas and Sovetsk are large cities along its course. The Neman is navigable c.60 mi (100 km) above Grodno. The meeting of Napoleon I and Czar Alexander I, which resulted in the Treaty of Tilsit (1807), took place on a raft in the middle of the river.