Comcor, Comandarm in the Red Army and Flagman 1st rank etc. in the Red Navy; the other senior functional ranks ("division commissar," "division engineer," etc.) remained unaffected. The arm or service distinctions remained (e.g. general of cavalry, marshal of armoured troops). For the most part the new system restored that used by the Imperial Russian Army at the conclusion of its participation in World War I. In early 1943 a unification of the system saw the abolition of all the remaining functional ranks. The word "officer" became officially endorsed, together with the use of epaulettes, which superseded the previous rank insignia. The ranks and insignia of 1943 did not change much until the last days of the USSR; the contemporary Russian Army uses largely the same system. Military education During the Civil War the commander cadres were trained at the Nicholas General Staff Academy of the Russian Empire, which became the Frunze Military Academy in the 1920s. Senior and supreme commanders were trained at the Higher Military Academic Courses, renamed the Advanced Courses for Supreme Command in 1925. The 1931 establishment of an Operations Faculty at the Frunze Military Academy supplemented these courses. The General staff Academy was reinstated on 2 April 1936, and became the principal military school for the senior and supreme commanders of the Red Army. Purges The late 1930s saw purges of the Red Army leadership which occurred concurrently with Stalin's Great Purge of Soviet society. In 1936 and 1937, at the orders of Stalin, thousands of Red Army senior officers were dismissed from their commands. The purges had the objective of cleansing the Red Army of the "politically unreliable elements," mainly among higher-ranking officers. This inevitably provided a convenient pretext for the settling of personal vendettas or to eliminate competition by officers seeking the same command. Many army, corps, and divisional commanders were sacked: most were imprisoned or sent to labor camps; others were executed. Among the victims was the Red Army's primary military theorist, Marshal Mikhail Tukhachevsky, who was perceived by Stalin as a potential political rival. Officers who remained soon found all of their decisions being closely examined by political officers, even in mundane matters such as record-keeping and field training exercises. An atmosphere of fear and unwillingness to take the initiative soon pervaded the Red Army; suicide rates among junior officers rose to record levels. The purges significantly impaired the combat capabilities