The Ninth Chief Directorate (also nicknamed Devyatki (Russian: девятки)) of the KGB was the organization responsible for providing bodyguard services to the principal Communist Party of the Soviet Union (CPSU) leaders (and families) and major Soviet government facilities (including nuclear-weapons stocks). It operated the Moscow VIP subway system, and the secure government telephone system linking high-level government and CPSU officers.
In mid-1992 the KGB's Ninth Directorate became the Main Guard Directorate (Glavnoye upravleniye okhraneniya, GUO) and in 1996 it was re-organized to the Federal Protective Service of Russia.
The original article can be found at Ninth Chief Directorate and the edit history here.