Therefore, the So clan established their dominance over the territory by obtaining the revenue arose from the trade with Korea in order to have a command of influential families and place local samurai under the clan's order (this is called the Territory of the So clan).
そのため、宗氏は通交権益の知行化を通じて有力庶家の掌握や地侍の被官化を行い、領国支配を推し進めていた（宗氏領国）。