established in 1564 under the rule of Tsar Ivan the Terrible to operate outside, in parallel and partly as a substitute to the Russian Tsardom civil, military and court apparatus. As a rule Oprichniks, including many of their highest leaders, were raised from low classes to serve the Tsar directly. Supposedly the Tsar needed them to crush powerful Russian nobles, mainly the Princes (Knyazes) and the Boyars, as well as traders grown too independent in the liberal northern cities such as Pskov and Novgorod. Because Oprichniks came from the low layers of society (Boris Godunov served as archer in the army before becoming one of the leaders of the Oprichnina and later himself ascending to the throne) and had no political support other than the Tsar himself they were fanatically loyal and hated nobles whom they saw as unjustly rich, powerful and corrupted. They believed in the Tsar as the only legitimate power in Russia. Because Ivan the Terrible was always suspicious of his entourage he created and entrusted this militant organization to defend him against the enemies. Oprichniks were supposed to be "pure" people, caring not for their personal well-being but for the Tsar and Russia.
Could history be repeating itself?
See also: Eurasia Daily Monitor. FINANSGROUP: HOW RUSSIA’S SILOVIKI DO BUSINESS. By Jonas Bernstein. Friday, November 30, 2007.