China came under foreign rule for the first time when Genghis Khan's descendents breached the Great Wall and took over. The Mongol army was a relatively small one -250,000 strong- which made the defeat more humiliating. Moslems and Europeans arrived in China, as did Western concepts and ideas.
c. 1368-1644:
The Ming Dynasty:
The Ming were the most active of all wall builders. The parts of the Great Wall as we know it today were built in the late 16th century. The Ming built walls in three stages: the first period was from 1368-1449, the second until the end of the 15th century, and the third from about 1540 on. Each period had its characteristic defence system.
c. 1466:
The Chinese signalling system was improved. Regulations introduced cannon fire; the number of shots depended on the strength of the enemy.
