In a 'family' in the court nobles' society of medieval Japan, the following two factors were important to support the existence of the family: its territory, which constituted the economic base; and the family, which could be called its social base.
中世日本の公家社会における「家」においては経済的基盤である家領と並んで社会的基盤とも呼ぶべき家門が家の存立を支える重要な存在であった。