Educated as an engineer at the Saint Petersburg Polytechnic Institute, Bielskis worked at a steal factory in Ukraine until he was able to return to Lithuania in 1905.

During World War I, he evacuated to Saint Petersburg where he was an active participant of the February Revolution and chairman of the Petrograd Seimas which attempted to organize a Lithuanian political center in Russia.

In 1923, he returned to Šiauliai where he was director of the Gubernija brewery and was elected to the city's council as a representative of the Social Democratic Party of Lithuania.

He participated in the smuggling of the banned Lithuanian press and maintained contacts with leftist activists, including the Zubov family.

[1] Together with Kazys Grinius and Povilas Višinskis, Bielskis attended the congress of zemstvos, organized by Pyotr Dmitriyevich Dolgorukov in October 1905.

[4] In fall 1905, Bielskis moved to Šiauliai where he became an administrator of the estates of Alexandra Zubova [lt] (mother of Vladimir Zubov) and an active participant in Lithuanian cultural life.

The Seimas attempted to establish a Lithuanian political center that would campaign for Lithuania's independence, but it broke down due to disagreements.

Due to the bitter dispute over Vilnius Region with the Second Polish Republic, Bielskis' body had to be transported via Latvia to Lithuania.

[7] Around 1896, in Saint Petersburg, Bielskis married Vera Ushakova (1877–1941), a Russian noble from Tver region who claimed descent from General Peter Ivelich.

[2] They met through Vincas Čepinskis [lt] who tutored his future wife Maria, a friend of Vera and a daughter of Valentin Korsh [ru].