The Yongle Emperor sponsors the massive and long term Zheng He expeditions  as part of his desire to expand Chinese influence.

These are China's only major seagoing explorations of the world (although the Chinese had been sailing to Arabia, Africa, and Egypt since the Tang Dynasty, from 618-907).

The first expedition launches in 1405 (eighteen years before Henry the Navigator will begin Portugal's voyages of discovery).

The expeditions are all under the command of China's greatest admiral, Zheng He.

At least seven expeditions will be launched, each bigger and more expensive than the last.

Some of the boats used are apparently the largest sail-powered boats in history (National Geographic, May 2004).