Since his first son Okitomo TANUMA was already dead and his other three sons were adopted out, his grandson Okiaki TANUMA was allowed to take over as head of the family, provided that their territory was reduced to a fief of 10,000 koku in the Mutsu province.
長男の田沼意知は既に死去していて、他の三人の子供は全て養子に出されていたため、孫の田沼意明が陸奥1万石に減転封のうえで家督を継ぐことを許された。