Though nearly obsolete by the beginning of World War II, the T-26 was the most important tank of the Spanish Civil War and played a significant role during the Battle of Lake Khasan in 1938 as well as in the Winter War. The T-26 was the most numerous tank in the Red Army's armoured force during the German invasion of the Soviet Union in June 1941. The Soviet T-26 light tanks last saw combat in August 1945, in Manchuria. The T-26 was used extensively in the armies of Spain, China and Turkey. In addition, captured T-26 light tanks were used by the Finnish, German, Romanian and Hungarian armies. Prewar years The first unit equipped with the T-26 was the 1st Mechanized Brigade named after K.V. Kalinovsky (the Moscow Military District). Tanks delivered to the Red Army through the end of 1931 were unarmed and intended for training, and the T-26 entered active service in 1932 only. The first series-produced T-26 tanks were shown to the public during the military parade on Red Square in Moscow on 7 November 1931—the 14th anniversary of the October Revolution. New mechanized brigades, each equipped with 178 T-26 tanks, were also organized at that time. The RKKA Staff decided to form larger tank units based on experience gained in military exercises of 1931–1932: so mechanized corps were created in the Moscow Military District, the Ukrainian Military District and the Leningrad Military District in autumn 1932. Each mechanized corps consisted of two mechanized brigades (one equipped with the T-26 and another with the BT). From 1935, mechanized corps were equipped only with BT tanks. When series production of the T-26 mod. 1933 started, each tank platoon consisted of three vehicles (one single-turreted mod. 1933 and two twin-turreted mod. 1931 tanks). Later, the majority of twin-turreted T-26 tanks were given to combat training depots and to tank battalions of rifle divisions (in the beginning of 1935 tank battalion of rifle division consisted of 3 companies, 15 T-26 tanks in each). In August 1938 mechanized corps, brigades and regiments were reorganized into corresponding tank units. In the end of 1938 the Red Army had 17 light tank brigades (267 T-26 tanks in each) and 3 chemical tank brigades (equipped with flame-throwing tanks based on the T-26 chassis). Spanish Civil War The Spanish Civil War was the first conflict in which the T-26 participated. At the request of the