In establishing a kamon (family), a deed that can be considered a historical incident is necessary: ascension to the throne, obtaining a government post or a certain mastermanship, or a territorial land or building such as a castle or a manor.
家門の創設に当たっては王位や官職、あるいは一定の支配権の獲得、領地の取得、城塞や館の建設など歴史的な事件となりうる行為をもっておこなわれる。