Complex sentence: Emelyan Pugachev was betrayed by his own Cossacks when he tried to flee in mid-September 1774, was caught and executed in January 10 1775, in Moscow.
Split into simpler sentences: Emelyan Pugachev was betrayed by his own Cossacks when he tried to flee in mid-September 1774. He was caught and executed on January 10 1775, in Moscow.