The Main Directorate of State Security (, Главное управление государственной безопасности, ГУГБ, GUGB) was the name of the Soviet most important security body within the People's Commissariat of Internal Affairs (NKVD) USSR. At the time of its existence, which was from July 10, 1934 to February 3, 1941, the GUGB reflected exactly the Secret Operational Directorate within OGPU under Council of People's Commissars, which operated within OGPU structure from 1923 to 1931/32. An intelligence service and secret police from July 1934 to February 1941, it was run under the auspices of the Peoples Commissariat of Internal Affairs (NKVD). Its first head was first deputy of People's Commissar of Internal Affairs (then – Genrikh Yagoda), Commissioner 1st rank of State Security Yakov Agranov. History The Main Directorate of State Security evolved from the Joint State Political Directorate (or OGPU). On February 3, 1941, the Special Sections (or OO) of the GUGB-NKVD (responsible for counter-intelligence in the military) became part of the Army and Navy (RKKA and RKKF, respectively). The GUGB was disbanded as an organization within NKVD USSR. The units that operated in GUGB were reorganized and made the core of the newly made People's Commissariat of State Security or NKGB. Following the outbreak of World War II, the NKVD and NKGB were reunited, not as GUGB but as totally separate directorates. On July 20, 1941, Army and Airforce counter-intelligence was returned to the NKVD as Directorate of Special Departments under Viktor Abakumov, in January 1942 Navy CI followed. In April 1943, it was again transferred to the Narkomat of Defence and Narkomat of the Navy, becoming SMERSH (from Smert' Shpionam or "Death to Spies"); at the same time, the GUGB was again separated from the NKVD as NKGB. GUGB heads By the end of 1937, the GUGB was the most powerful and influential organ in the NKVD structure. GUGB departments (or Sections) dealt with - intelligence, internal security, counter-intelligence, protection of government and secret communications. The first chief of the GUGB was Yakov Agranov, Commissioner 1st rank of State Security and first deputy of People's Commissar of Internal Affairs. The next chief of the GUGB from April 15, 1937, to September 8, 1938, was komkor Mikhail Frinovsky, he was succeeded by Lavrenty Beria, then just promoted to Commissioner 1st rank of State Security. When Beria became People's Commissar of Internal Affairs (head of NKVD), Commissioner 3rd rank of State Security