GRU
The GRU's first predecessor in post-tsarist Russia was created on October 21, 1918 under the sponsorship of Leon Trotsky, who was then the civilian overseer of the Red Army. It was originally known as the Registration Directorate (Registrupravlenie, or RU). In his history of the early years of the GRU, Raymond W. Leonard writes:"As originally established, the Registration Department was not directly subordinate to the General Staff [of] the Red Army... In 1921... it was elevated in status to become the Second (Intelligence) Directorate of the Red Army Staff.