Who they were
Zhu Di, fourth son of the Ming founder, held the north as Prince of Yan at Beiping, modern Beijing. In the Jingnan civil war (1399–1402) he took the throne from his nephew, the Jianwen Emperor.
What they did
He moved the capital from Nanjing to Beijing (formally in 1421) and built the Forbidden City (1406–1420). He commissioned the Yongle Encyclopedia, completed in 1408 — more than 22,000 juan, the largest reference work of its age — and dispatched Zheng He’s treasure fleets from 1405. To supply the new capital he had the Grand Canal dredged and reopened. He led five personal campaigns into Mongolia and died on the last, in 1424.
Legacy
Beijing has been China’s capital ever since, and his reign stands as the Ming’s high-water mark of outward power.