Vietnamese era name

Vietnamese era names were titles adopted in historical Vietnam for the purpose of year identification and numbering.

Era names originated in 140 BCE in China, during the reign of the Emperor Wu of Han.^[1][2] Since the middle of the 6th century CE, independent Vietnamese dynasties started to proclaim their own era names.^[2][3][4]

During periods of direct Chinese rule, Chinese era names would gain official use in Vietnam, as was the case for other parts of China.