the rest used one era name.) This was known as the yī shì yī yuán zhì (一世一元制; lit. "one-era-name-for-a-lifetime system"). On 24 June 1398 (Hongwu 31...

having only one era name for one monarch—known as the yí shì yì yuán zhì (一世一元制; lit. "one-era-name-for-a-reign system"). Thus, modern historians would...

more than two era names during their reigns, until the yī shì yī yuán zhì (一世一元制; lit. "one-era-name-for-a-lifetime system") was established during the Hongwu...

the era name was changed to "Meiji" (明治), and a "one reign, one era name" (一世一元, issei-ichigen) system was adopted, wherein era names would change only upon...