Arguably the first secret police in Russia, these were the enforcers of Ivan the Terrible in the late 16th century. Ivan had divided Russia into two parts; one ruled over by the Council of Boyars, the other ruled by himself, which was called the oprichnina. In a country where betrayal was common, the oprichniki served as Ivan's private army, and he used them to root out and execute anyone he deemed guilty of treason.

Thanks to an anonymous nodesheller and