Hongwu

Hongwu (23 January 1368 – 5 February 1399) was the era name (nianhao) of the Hongwu Emperor (reigned 1368–1398), the Chinese emperor who founded the Ming dynasty that ruled China from 1368 to 1644. It was also the first era name of the Ming.

On 23 January 1368 (Wu 2, 4th day of the 1st month), Zhu Yuanzhang proclaimed himself emperor of the Great Ming dynasty in Yingtian Prefecture, with the era name "Hongwu". During the Hongwu period, there was no war in the country, and society quickly recovered from the war in the late Yuan dynasty. The population increased rapidly and the economy developed quickly. This period is known in historiography as the "Reign of Hongwu" (洪武之治).

The emperors only used one era name during their reigns since the Hongwu Emperor began to form a practice. (Emperor Yingzong of Ming had two era names due to his abdication and later restoration, while 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, 10th day of the 5th leap month), the Hongwu Emperor died. On 30 June (16th day of the 5th leap month), Imperial Grandson-heir Zhu Yunwen ascended the throne as the Jianwen Emperor. The following year, the era was changed to Jianwen.

On 18 July 1402 (Jianwen 4, 18th day of the 6th month), the Yongle Emperor, who had usurped the throne through the Jingnan campaign, abolished the Jianwen era name and renamed it Hongwu 35. The following year, the era was changed to Yongle. According to Xia Xie (夏燮)'s Ming Tongjian (明通鑑), since Zhu Di had started his rebellion at Beijing in 1399 (Jianwen 1), he had begun restoring the Hongwu era name in his conquered areas, and after the Jingnan campaign, he had ordered the whole country to reuse the Hongwu era name.

Contemporaneous eras

 * China
 * Yuan dynasty/Northern Yuan
 * Zhizheng (至正; 1341–1370): era name of Toghon Temür (Emperor Shun of Yuan)
 * Xuanguang (宣光; 1371–1379): era name of Biligtü Khan Ayushiridara (Emperor Zhaozong of Yuan)
 * Tianyuan (天元; 1379–1388): era name of Uskhal Khan Tögüs Temür (Prince of Yi)
 * Ming Xia
 * Kaixi (開熙; 1367–1371): era name of Ming Sheng (明昇)
 * Ming period
 * Tianding (天定; 1386): era name of Peng Yulin (彭玉琳)
 * Longfeng (龍鳳; 1397): era name of Tian Jiucheng (田九成)
 * Vietnam
 * Trần dynasty
 * Đại Trị (大治; 1358–1369): era name of Trần Dụ Tông
 * Đại Định (大定; 1369–1370): era name of Dương Nhật Lễ
 * Thiệu Khánh (紹慶; 1370–1372): era name of Trần Nghệ Tông
 * Long Khánh (隆慶; 1373–1377): era name of Trần Duệ Tông
 * Xương Phù (昌符; 1377–1388): era name of Trần Phế Đế
 * Quang Thái (光泰; 1388–1398): era name of Trần Thuận Tông
 * Kiến Tân (建新; 1398–1400): era name of Trần Thiếu Đế
 * Japan
 * Southern Court
 * Shōhei (正平; 1346–1370): era name of Emperor Go-Murakami and Emperor Chōkei
 * Kentoku (建徳; 1370–1372): era name of Emperor Chōkei
 * Bunchū (文中; 1372–1375): era name of Emperor Chōkei
 * Tenju (天授; 1375–1381): era name of Emperor Chōkei
 * Kōwa (弘和; 1381–1384): era name of Emperor Chōkei and Emperor Go-Kameyama
 * Genchū (元中; 1384–1392): era name of Emperor Go-Kameyama
 * Northern Court
 * Jōji (貞治; 1362–1368): era name of Emperor Go-Kōgon
 * Ōan (応安; 1368–1375): era name of Emperor Go-Kōgon and Emperor Go-En'yū
 * Eiwa (永和; 1375–1379): era name of Emperor Go-En'yū
 * Kōryaku (康暦; 1379–1381): era name of Emperor Go-En'yū
 * Eitoku (永徳; 1381–1384): era name of Emperor Go-En'yū and Emperor Go-Komatsu
 * Shitoku (至徳; 1384–1387): era name of Emperor Go-Komatsu
 * Kakei (嘉慶; 1387–1389): era name of Emperor Go-Komatsu
 * Kōō (康応; 1389–1390): era name of Emperor Go-Komatsu
 * Meitoku (明徳; 1390–1394): era name of Emperor Go-Komatsu
 * Post-Meitoku unification
 * Ōei (応永; 1394–1428): era name of Emperor Go-Komatsu and Emperor Shōkō