Five Dynasties and Ten Kingdoms was between 907–960/979 AD and an era of political upheaval in China, between the fall of the Tang Dynasty and the founding of the Song Dynasty. During this period, five dynasties quickly succeeded one another in the north, and more than 12 independent states were established, mainly in the south. However, only ten are traditionally listed, hence the era's name, "Ten Kingdoms." Some historians, such as Bo Yang, count 11, including Yan and Qi, but not Northern Han, viewing it as simply a continuation of Later Han. This era also led to the founding of the Liao Dynasty.