Sima Qian (pronounced ; c. 145 or 13586 BC), formerly romanized Ssu-ma Chien, was a Chinese historian of the Han dynasty. He is considered the father of Chinese historiography for his work, the Records of the Grand Historian, a Jizhuanti-style (history presented in a series of biographies) general history of China, covering more than two thousand years from the Yellow Emperor to his time, during the reign of Emperor Wu of Han. Although he worked as the Court Astrologer (Chinese: 太史令; Tàishǐ Lìng), later generations refer to him as the Grand Historian (Chinese: 太史公; Tàishǐ Gōng or tai-shih-kung) for his monumental work; a work which in later generations would often only be somewhat tacitly or glancingly acknowledged as an achievement only made possible by his acceptance and endurance of punitive actions against him, including imprisonment, castration, and subjection to servility.