南都 ("Southern Capital") is not a single place but a label reused across dynasties. In the Eastern Han, it referred to
南阳 (Emperor Guangwu's hometown) —
张衡's famous rhapsody
《南都赋》 describes that city. In the Ming, after the capital moved north to Beijing,
南京 was called
南都. The term thus marks wherever the "southern" half of a dual-capital system sat.
