Complex sentence: In 38 BC, while Emperor Yuan was watching a fight between wild animals, accompanied by a number of his concubines (but apparently not by Empress Wang Zhengjun), a wild bear broke loose and tried to get out of the cage.
Split into simpler sentences: In 38 BC, Emperor Yuan was watching a fight between wild animals, accompanied by a number of his concubines (but apparently not by Empress Wang Zhengjun). A wild bear broke loose and tried to get out of the cage.