Huang-di, (黃帝/黄帝 huángdì) or the Yellow Emperor, is a legendary Chinese sovereign and cultural hero who is thought to be the ancestor of all Han Chinese. One of the legendary Five Emperors, it was written in the "Shiji" by historian Sima Qian (145 BC-90 BC) that Huangdi reigned from 2497 BC to 2398 BC. His personal name was said to be Gongsun Xuanyuan (公孙轩辕). He became the chief deity of Taoism during the Han Dynasty (202 BC-220 AD). 