Chinese uniformity () is a term referring to the traditional phenomenon and political thought of uniformity and unification in the Chinese history. Since the Western Zhou dynasty (c. 1046 BC–771 BC) there has been a uniformity of various systems in the land of China, including the uniformity of the calendar, the uniformity of decrees, the uniformity of thought, the uniformity of etiquette, the uniformity of metrology, and the uniformity of writing system. The Qin dynasty (221 BC–206 BC) was the first imperial Chinese dynasty to reign over a unified China following its wars of unification. Since then China has a long history of a unified empire in addition to a common culture and traditions shared by many Chinese. Confucianism became China's official ideology in education and court politics during the Han dynasty. Even though Chinese people spoke a variety of dialects, the literate classes shared a written language known as the Classical Chinese, and an examination system based on Chinese classics served as the main path to official positions since the Sui dynasty.