Complex sentence: The invading Manchu army, with the help of Ming general Wu Sangui, captured Beijing, thus beginning the Qing Dynasty (also known as the Manchu Dynasty), which would be the last imperial dynasty of China.
Split into simpler sentences: The invading Manchu army, with the help of Ming general Wu Sangui, captures Beijing. This marks the beginning of the Qing Dynasty (also known as the Manchu Dynasty), the last imperial dynasty of China.