Chinese era names, also known as reign mottos, were titles used by various Chinese dynasties and regimes in Imperial China for the purpose of year identification and numbering. The first monarch to adopt era names was the Emperor Wu of Han in 140 BCE, and this system remained the official method of year identification and numbering until the establishment of the Republic of China in 1912 CE, when the era name system was superseded by the Republic of China calendar. Other polities in the Sinosphere—Korea, Vietnam and Japan—also adopted the concept of era name as a result of Chinese politico-cultural influence.
