Byambyn Rinchen was born in 1905 in Bol'shoy Lug place of Troitskosavsky uyezd (district), today the surroundings of Kyakhta, in the border zone of Russia and Mongolia (Kyakhta in Buryatia and Altanbulag sum in Selenge Province).
At that time he also met Konstantin Rokossovsky, then the commander of the 35th Independent Cavalry Regiment of the Red Army.