Complex sentence: During the pacification, a war broke out between China and Tibet in the Sino-Tibetan War, which saw Ma Bufang defeat the Tibetans and expand even deeper into Tibetan lands.
Split into simpler sentences: During the pacification, a war broke out between China and Tibet. This came to be known as the Sino-Tibetan War, and it was during this conflict that Ma Bufang defeated the Tibetans and was able expand his influence even deeper into Tibetan lands.