[2] The Ming dynasty era name remained relatively unchanged and was typically used for a longer period of time.
[7] The change of era usually occurred in the year following a new emperor's ascension to the throne, but there were a few instances of special circumstances.
[8][9][10] In 1457, after the Duomen Coup (奪門之變), Emperor Yongzong was restored to the throne and the era was changed to Tianshun that year.
[18][19][20] Even outer vassals like Joseon and the Ryukyu Kingdom adopted the Ming dynasty era name.
The period of use for each era name is based on the History of Ming, compiled by Zhang Tingyu, and Nanjiang yishi (南疆逸史), written by Wen Ruilin (溫睿臨).