nianhao
nianhao, literally “year designation,” is the Chinese term for the era name system that was used by Chinese emperors to mark the years of their reigns. The practice began during the late Western Zhou period and was formalized in the Qin dynasty, when emperor Qin Shi Huang declared a single era name for his entire reign: Qin Shi Huang. By the Han dynasty, it became customary for each emperor to select one or more era names, often reflecting auspicious meanings such as "Wuying" (無懿) or "Tianhe" (天河). The era name was listed on official documents, stelae, and coinage, and the years of a given era were counted from the first year of that name. For example, the year 65 CE in the Chinese calendar was the 15th year of the "Yongyuan" (永元) era of Emperor Guangwu.
The nianhao system remained in use throughout imperial China, with each emperor having the authority to adopt
In modern Chinese historiography, the nianhao is a key chronological marker. Scholars rely on era names to