Nurhaci (1558-1626), was a Manchurian warlord who united all the Jurchen tribes of the region and established the Manchu dynasty that would eventually conquer Ming China under the leadership of his sons and grandsons.
Born in 1558 to the Gioro clan of Jurchens, Nurhaci spent his youth as a soldier in the service of Li Chengliang, a Chinese general of Korean dissent who was stationed in Manchuria by the Ming emperor to keep peace with the warlike Jurchen tribes. Nurhaci eventually returned to assume headship of his tribe and spent most of his middle aged years fighting battle after battle against the other clans and tribes, eventually uniting them all under his rule and proclaiming himself Khan of the Later Jin Dynasty in 1616. Nurhaci then turned his energies to expanding his new empire, fighting a series of campaigns in which he extended his rule into northern Korea and up to the very edges of China proper.
As adept as he was at warfare, Nurhaci was equally gifted as an administrator, organizing the once chaotic Jurchen tribes into a more civilized society with ranks and titles and offices based on Chinese models and crafted with the advice of captured Chinese officials.
Nurhaci's greatest innovation was the creation (in 1615) of the famous "Eight Banners" system of organizing and centralizing his military by dividing it into eight units based on different colored banners, which were further divided into smaller sub-units. Although the banner system was originally strictly a military hierarchy, it eventually evolved into a bureaucracy in charge of paying wages, distributing land, overseeing public welfare projects, and administering justice, and continued to be used for these functions throughout the Qing Dynasty established in China by his sons.
Nurhaci died in 1626 at the age of 68 when he was struck by a cannonball while campaiging against the Ming at the Battle of Ningyuan. The battle was a major setback to the Jin in their war against the Ming, but under the able leadership of his sons Huang Taiji and Dorgon, would eventually triumph over the Ming and establish the Qing Dynasty in 1644.