Saibei

'region north of the Great Wall of China'), also known as Saiwai (塞外) and Yibei (迤北), is a geographical term used in Chinese history.

This boundary marks the northern limit of the frontier fortress, and the area beyond it is known as Saibei.

However, unlike directional terms such as northeast and southwest, Saibei has a deeper meaning as a border between the Han agricultural civilization and the northern nomadic tribes.

After the founding of the People's Republic of China, the administrative division was reset and the other four provinces were abolished (except for "Ningxia", which remained as a provincial name but with a greatly reduced area).

When the Republic of China was established, it encompassed the five provinces of Rehe, Chahar, Suiyuan, Ningxia, and Mongolia.