The name for Russian territory
that was under the direct administration
of Ivan the Terrible
for a brief time during the mid 16th century
In the 1560s, desertion and betrayal were so common in Russia that the Tsar announced his abdication of the throen in 1564, after one of his particularly talented field commanders defected to Poland. Citizens of Moscow and The Church worrying that the absense of Ivan would cause troublesome instability (this was before he went insane), begged him to stay. Ivan agreed, but only under the condition that he would have free reign to deal with traitors, and that a certain amount of land would come under his direct control as crown land. Thus, the Oprichnina was born in 1565.
Ivan then used taxes and labor from the land to launch a campaign of terror against all who had opposed him before. Entire cities were destroyed by the oprichniki troops, and many thousands of citizens and boyars were executed.
After only seven years, the oprichnina was abolished when the oprichniki failed to defend Moscow from the Tartars. The oprichnina was incorporated back into the rest of the country, but, understandably, Ivan didn't have the same problems with treachery that he did before.
Thanks to www.britannica.com