 In 1919 Chagdarjav joined the secret revolutionary group "Konsulyn Denj" (Consulate Hill) in Khüree (present-day Ulaanbaatar).Together with Dogsomyn Bodoo, Khorloogiin Choibalsan, and Darizavyn Losol he formed the basic nucleus of the group which joined with Damdin Sükhbaatar's "Züün Hüree" organization in June 1920 to form the Mongolian People's Party (MPP).Chagdrajav was one of seven revolutionaries (the famous "First Seven") chosen to travel to the USSR in June 1920 to establish contact with the Soviets.