Complex sentence: In his later years, Emperor Wenxuan suffered from alcoholism and possibly insanity, and Chinese history recorded his bloody rages, nevertheless his reign, carried out primarily by his Chinese advisers, was considered well-administered.
Split into simpler sentences: In his later years, Emperor Wenxuan suffered from alcoholism and possibly insanity. Chinese historical annals recorded his bloody rages, nevertheless his reign, carried out primarily by his Chinese advisers, was considered well-administered.