Complex sentence: She left Australia for the stage in England in 1926, her first show there was poorly received, but when she appeared in Franz Lehár's "The Blue Mazurka" in 1927, her success in England was assured.
Split into simpler sentences: She left Australia for the stage in England in 1926. Her first show there was poorly received, but when she appeared in Franz Lehár's "The Blue Mazurka" in 1927, her success in England was assured.