Historically, China has been a major empire in history, and throughout its history, China developed from the northern basin of the Huaxia, which is believed to be between modern Yellow and Yangtze rivers, slowly became a major power from ancient era. To achieve that, various ethnic Han Chinese dynasties had perpetuated the expansions of the nation, until it was unified under the Qin dynasty. However, it was only the Qin dynasty that China truly started its process of expansion into other nations. Qin dynasty's expansionism eventually led to its first contacts with the ancient Viet tribes, and further extended to ancient Koreans, as well as the Xiongnus. The Qin dynasty laid the foundation for future territorial expansions by subsequent Chinese dynasties.