Wanli (simplified Chinese: 万历; traditional Chinese: 萬曆; pinyin: Wànlì; Wade–Giles: Wan-li; lit. 'ten thousand calendars'; 2 February 1573 – 27 August 1620; Qing dynasty avoided the naming taboo of Hongli 弘曆, the Qianlong Emperor, and wrote 曆 as 歷, 厯, 厤) was the era name (nianhao) of the Wanli Emperor, the 14th emperor of Ming dynasty. The Wanli era lasted for 48 years, making it the longest era of the Ming. During the early years of the Wanli era, Zhang Juzheng implemented a series of reform measures that resulted in continuous social and economic development and military victories, and the imperial court showed a restoration atmosphere. This period of prosperity became known as the "Wanli Restoration" (萬曆中興). However, a dispute over succession (國本之爭) arose, and the Wanli Emperor was prevented by his powerful advisors from naming his beloved son as crown prince. In a fit of anger, he refused to attend court for thirty years, resulting in a period of neglect known as the "Wanli's negligence" (萬曆怠政). During this time, factionalism among government officials was allowed to rise, leading to the Donglin factional strife (東林黨爭) and the use of the Three Cases of the Late Ming (明末三案) to further their own agendas. These actions ultimately contributed to the downfall of the Ming dynasty.
On 28 August 1620 (Wanli 48, 1st day of the 8th month), the Taichang Emperor ascended to the throne and continued to use the Wanli era name. The following year, the era was changed to Taichang. However, the Taichang Emperor died on 26 September (1st day of the 9th month) and reigned for only 30 days. On 1 October (6th day of the 9th month), the Tianqi Emperor ascended to the throne, and on 25 October (20th day of the 9th month), he issued an edict to change the era to "the first year of the Taichang era" from "the 8th month of the 48th year of the Wanli era" onwards, and the following year, the era was changed to Tianqi.[1][2]