This History Channel documentary explains the discovery and exhumation of four different tombs in China that contain well-preserved mummies of aristocrats from the Han Dynasty, which was over two thousand years ago.  The four tombs explained are of Xin Zhui, Liu Sheng, “Shui,” and Ling Huiping.  The documentary shows footage of the mummies being examined, and it explains how the Chinese had advanced knowledge of mummification techniques where the bodies seem as if they had only recently died.

[NOTE: This documentary is actually only about 45 minutes long, it is presented twice in a row in this video.]