In an attempt to reduce the reliance on the mistrusted ex-Tsarists they reduced the officer corps and educated new cadets.[1] Leon Trotsky's removal from the Commissariat of Defence was in part driven by his perceived over-reliance on Tsarist officers. His replacement, Mikhail Frunze, further decreased their number in army. By 1930, ex-Tsarists made up only about 10 percent of the officer corps.[3]