Complex sentence: Kulik was dismissed from his posts in 1946 after "NKVD" telephone eavesdroppers overheard him grumbling that politicians were stealing the credit from the generals, arrested in 1947 and remained in prison until 1950, when he was condemned to death and executed for treason.
Split into simpler sentences: Kulik was dismissed from his posts in 1946 after "NKVD" telephone eavesdroppers overheard him grumbling that politicians were stealing the credit from the generals. Arrested in 1947, he remained in prison until 1950, when he was condemned to death and executed for treason.