Complex sentence: After being temporarily defeated by the Mongol army, he fled to Huangmei Mountain (黃梅山), but returned in 1355 to invade once again and move the capital to Hanyang.
Split into simpler sentences: After being temporarily defeated by the Mongol army, he fled to Huangmei Mountain (黃梅山). He returned in 1355 to invade once again and moved the capital to Hanyang.