During this time, Nanjing was the international hub of East Asia.
Nanjing boasts many high-quality universities and research institutes, with the number of universities listed in 100 National Key Universities ranking third, including Nanjing University which has a long history and is among the world top 10 universities ranked by Nature Index.
Although Beijing was the de facto capital after that, Nanjing remained the official one of the Ming Empire until 1441, when Emperor Yingzong ordered to not to prefix the words "行在" ("provisional") on the Beijing Government seals any longer, while Nanjing's need to prefix "Nanjing" for distinguishing purposes remained.
Hence, Nanjing still had itself imperial government with extremely limit power before 1644.
It was home of the admiral Zheng He, who went to sail the Pacific and Indian Oceans, and it was visited by foreign dignitaries, such as a king from Borneo (Boni 渤泥), who died during his visit to China in 1408.
The Tomb of the King of Boni, with a spirit way and a tortoise stele, was discovered in Yuhuatai District (south of the walled city) in 1958, and has been restored.