Wuyuan (era)

Wuyuan (31 January 1367 – 23 January 1368) was the regnal year used by the Western Wu regime prior to Zhu Yuanzhang's establishment of the Ming dynasty. On New Year's Day of 1364 (Han Song Longfeng 10, Yuan Zhizheng 24), Zhu Yuanzhang proclaimed himself the Prince of Wu (吴王) in Yingtian Prefecture and established the Western Wu regime. He nominally respected the Han Song regime but suspended the Longfeng era name. In December 1366 (Han Song Longfeng 12, Yuan Zhizheng 26), Han Lin'er, emperor of Han Song, was drowned in a shipwreck while crossing the Yangtze River. Zhu Yuanzhang took the next year (1367) as "Wu 1" (吳元年, "the first year of Wu" or "the first year of the Prince of Wu's reign" ). On 23 January 1368 (Wu 2, 4th day of the 1st month), Zhu Yuanzhang proclaimed himself emperor in Yingtian Prefecture, establishing the Ming dynasty with the era name "Hongwu".

According to the documents, Zhu Yuanzhang stopped using the Longfeng era name, and used the dynastic name "Wu" era, called "Wu 1" (吳元年) and "Wu 2" (吳二年). Only Yu Ben (俞本)'s Ji shi lu (紀事錄) records the change of era to "Wuyuan" (吳元), called "Wuyuan 1" (吳元元年, "the first year of Wuyuan") and "Wuyuan 2" (吳元二年, "the second year of Wuyuan"). Zhu Honglin (朱鴻林) believes that "Wuyuan yuannian" (吳元元年) was not a clerical error; whether it was the official era name "Wuyuan" or "Wu", which was the dynastic name instead of the era name, it does not deviate from the meaning of Zhu Yuanzhang's self-proclaimed Prince of Wu during his lifetime.

Later, Zhu Yihai's Lu era imitated Zhu Yuanzhang's change of era without era name.

Change of era

 * 31 January 1367 (Longfeng 13, 1st day of the 1st month): The era was changed to "Wu 1" (吳元年, "the first year of Wu").
 * 23 January 1368 (Wu 2, 4th day of the 1st month): The era was changed to Hongwu 1 (洪武元年, "the first year of Hongwu").

Other regime eras that existed during the same period

 * China
 * Zhizheng (至正; 1341–1370): Yuan dynasty — era name of Emperor Shun of Yuan
 * Kaixi (開熙; 1367–1371): Ming Xia — era name of Ming Sheng (明昇)
 * Vietnam
 * Đại Trị (大治; 1358–1369): Trần dynasty — era name of Trần Dụ Tông
 * Japan
 * Shōhei (正平; 1346–1370): Southern Court — era name of Emperor Go-Murakami and Emperor Chōkei
 * Jōji (貞治; 1362–1368): Northern Court — era name of Emperor Go-Kōgon