The Five Dynasties and Ten Kingdoms period (907–979) was an era of political upheaval and division in 10th-century Imperial China. Five states quickly succeeded one another in the Central Plain, and more than a dozen concurrent states were established elsewhere, mainly in South China. It was the last prolonged period of multiple political divisions in Chinese imperial history. The last of the Five Dynasties and Ten Kingdoms regimes was Northern Han, who held out until 979 when Song officially conquered it, thereby reclaiming all of the territory of the former Tang dynasty.