Hung-Wu (National Palace Museum, Taipei)
After Hung-Wu threw the Mongols out in 1368 AD, he established the Ming Dynasty. But Hung-Wu's power was still pretty weak after the Mongol invasion. He only ruled China from the Great Wall to the east of Tibet - smaller borders than modern China or than T'ang Dynasty China. Hung-Wu modelled his government on the T'ang Dynasty, trying to keep as much power as possible in the central government and especially in his own hands. To deal with the extra work this made for him, he created a council of his advisers to help him. Examinations came back as a way to select governors and judges.
In 1451 AD, after a civil war, the emperor Yung-Lo moved the capital from Nanjing to Beijing (bay-ZING), where he began work on the imperial palace, which still stands today.
To find out more about the Ming dynasty in China, check out these books from Amazon.com or from your library:
Eyewitness: Ancient China, by Arthur Cotterell, Alan Hills, and Geoff Brightling (2000). For kids.
China (History of Nations), by Greenhaven Press (2002). For middle schoolers. The negative review on Amazon is actually for a different book - don't be alarmed!
The Examination, by Malcolm Bosse (1994). A young adult novel about a young man taking the government examinations, and his more adventurous brother. The writing's not great, but it's a good introduction to medieval China under the Ming Dynasty.
The Confusions of Pleasure: Commerce and Culture in Ming China, by Timothy Brook (1999). The best available survey of Ming Dynasty China for adults.
The Cambridge History of China: Volume 7, The Ming Dynasty, 1368-1644, Part 1, edited by Frederick W. Mote, Denis Twitchett, and John K. Fairbank (1988). Everything anyone knows about the Ming Dynasty.