李世民 (Lĭ Shìmín) is famous for fratricide, concubines, and wealth! The son of the first emperor of the Táng Dynasty, Lĭ Shìmín played a large role in encouraging his father to rebel against the Suí Dynasty, bringing them down in 618 AD.
Afterwards, a serious brother-war broke out: An older brother tried to poison him, while a younger brother gave him a dangerous horse in the hope it would throw him off. Lĭ Shìmín got back at both of them by killing them in an ambush and forcing his father to make him the emperor. Power hungry much?
Definitely, but his historical reputation is still pretty good: He spent his reign beating up the Turkic peoples to the North and the North Koreans to the East, and his rule is considered to have started a golden age for China, setting a standard for future leaders. Oh, and he had hundreds of concubines.
See how the hat fashion has changed since the Qin Emperor last week? Baidu Baike