Huang–Lao school is a school of philosophical and political thought originating in the Warring States Period (475–221 BC), also known as the study of Huang–Lao. "Huang" refers to Huangdi, also known as the Yellow Emperor, and "Lao," Laozi, the founder of Taoism. Members of the Huang–Lao group regarded Laozi as their grand master and attributed its genesis to the legendary figure, Huangdi. Therefore, they named the school Huang–Lao.