Complex sentence: As a result, the party made concessions to local "crime bosses" such as the notorious Du Yuesheng in Shanghai and developed relationships with such organizations that persisted after the party fled to Taiwan following the Chinese Civil War.
Split into simpler sentences: As a result, the party made concessions to local "crime bosses", such as the notorious Du Yuesheng in Shanghai. The relationships with such organizations is believed to persist KMT fled to Taiwan following the Chinese Civil War.