1, the so-called east, west, north and south, is often named after the relative changes of the capital. 2. In the history of China, the Central Plains was often invaded by foreigners, usually in the north and west. Therefore, after the former regime was successfully defeated by foreign countries, it would move eastward and southward. After the Western Zhou Dynasty, there was the Eastern Zhou Dynasty, after the Western Han Dynasty, there was the Eastern Han Dynasty, and after the Northern Song Dynasty, there was the Southern Song Dynasty. 3. From the five elements, the fires in the east, the fire in the south, the Wuji soil in the middle, the gold in the west, the agricultural water in the north, and the water fire in Jin Kemu are usually fought from north to south and from west to east. Geographically, this is related to climate, soil and water. For example, the northwest eats wheat and the southeast eats rice, so usually the northwest is a big shot and the southeast is a weak scholar. The result of fighting is self-evident.