Complex sentence: The film is inspired by a controversial legend about Emperor Jianwen of Ming Dynasty, who is rumored to have fled to Southeast Asia when he was dethroned by his own uncle in the year 1402.
Split into simpler sentences: The film is inspired by a controversial legend about Emperor Jianwen of Ming Dynasty. According to it, he had fled to Southeast Asia when he was dethroned by his own uncle in the year 1402.