The author describes activity of Poles who lived in Belarusian territories in 1918–1920. They were a group of cultural and economic importance who promoted the idea of maintaining Lithuania and Belarus in the Polish sphere of influence. They organized councils and committees and, later on, armed groups, wrote memorials and called upon the Polish government to save Belarus from the Bolsheviks. In their opinion, the entire region had to either be a part of Poland or an independent allied state. According to them, the Treaty of Riga which divided Belarus was a failure of Poland’s foreign policy.