Definitive stamps of Russia
Definitive stamps of Russia are the regular postage stamp issues produced in the Russian Empire and RSFSR between 1857 and 1923, and in the Russian Federation since 1992. == Russian Empire == The Russian Empire started issuing definitive series of postage stamps since 10 December 1857 when the first Russian stamp went on sale.
Source: Wikipedia — Definitive stamps of Russia (CC BY-SA 4.0)