In what aspects did the unified dynasties of past dynasties regard the work of "moving the people to the real border" as a long-term plan and strategic measure?

First, choose the immigration location of the strategic frontier. For example, the Western Han Dynasty once migrated from Huanghuai Plain to northern Shaanxi, Longyou and Hetao on a large scale to enrich Guanzhong and border counties.

The second is to formulate various supporting preferential policies to ensure the actual effect of immigration to the frontier. For example, the Tang government stipulates that the local government in the origin of immigrants must provide clothes, cattle, rations, seeds, daily necessities and low-interest loans to recruited immigrants (children of ethnic minorities and Han nationality) to help them settle down; Officials recruited craftsmen from all over the country to accompany the immigrants to the resettlement sites, so that they could make weapons and farm tools in military cities to serve the immigrants; After the immigrants settle down, there is still surplus grain besides self-sufficiency. The state should buy and reward reclamation at double price and do everything possible to support small farmers in the border areas.

The third is to strengthen the organization and management of immigration work. The government selects competent grass-roots officials, organizes immigrant production, establishes a perfect organization under the jurisdiction of the village administration system, popularizes the Central Plains system in frontier immigrant areas, and constantly turns the frontier into the mainland. The fourth is to organize immigrants to conduct military training. "Choose their talents and have guardians, learn the terrain and know the people's hearts, live in the country and learn the law, and teach the people to meet them. Therefore, if you are a pawn, you must be strong outside and hollow inside. Get used to it and don't let it migrate. " That is, using the resettlement psychology of immigrants after settlement, perfecting civil defense organizations, conducting appropriate military training and consolidating border defense.