Ligdan Khan
Ligdan Khan occupied Tumet and Ordos in 1623 to forestall their absorption by the Manchu and advanced into the Manchurian lands in 1631. Nevertheless, Manchu ruler Hong Taiji, successor of Nurhaci, allied with the Inner Mongolian "taiji"s defeated him again in 1634 and sacked Hohhot. The Manchus secured control over Inner Mongolia in 1632 and Ligdan's army moved to fight Tibetan Gelugpa sect (Yellow Hat sect) forces. The Gelugpa forces supported the Manchus, while Ligdan supported the Kagyu sect (Red Hat sect) of Tibetan Buddhism. Ligdan Khan died in 1634 on his way to Tibet when his troops were swept by an epidemic.