The streltsy were the units of Russian firearm infantry from the 16th century to the early 18th century and also a social stratum, from which personnel for streltsy troops were traditionally recruited. They are also collectively known as streletskoye voysko. These infantry troops reinforced feudal levy horsemen or pomestnoye voysko. The first units were established by Ivan the Terrible as part of the first standing army in Russia.

Ivan IV Vasilyevich, commonly known as Ivan the Terrible, was Grand Prince of Moscow and all Russia from 1533, and Tsar of all Russia from 1547 until his death in 1584. He was the first Russian monarch to be crowned as tsar.