During 1926–1948 the Chairman of the Collegium was Vasili Ulrikh. The role of the Military Collegium drastically changed since June 1934, when it was assigned the duty to consider cases that fell under Article 58, counter-revolutionary activity. During the Great Purge of 1937–1938 the Military Collegium tried relatively prominent figures, usually based on the lists approved personally by Joseph Stalin, the majority of Article 58 cases having been processed extrajudicially by NKVD Troikas. In particular, the Military Collegium conducted the major Soviet show trials.