This book mainly tells about the history of the Northern Dynasties for about 140 years, and details the rise of the Northern Wei, its split (Eastern Wei, Western Wei), the demise of the Northern Wei (replaced by the Northern Qi and the Northern Zhou), and the process of Yang Jian becoming powerful in the Northern Zhou Dynasty and usurping the Zhou Dynasty to unify the world. This is a history of great ethnic migration, great integration of ethnic groups, and great ideological and social changes. It experienced painful turmoil, turning points and reforms, and brewed the unified Sui and Tang Dynasties.
