 A year after placing Shōshi in the imperial harem, in an effort to undermine Teishi's influence and increase Shōshi's standing, Michinaga had her named Empress although Teishi already held the title.As historian Donald Shively explains, "Michinaga shocked even his admirers by arranging for the unprecedented appointment of Teishi (or Sadako) and Shōshi as concurrent empresses of the same emperor, Teishi holding the usual title of "Lustrous Heir-bearer" "kōgō" and Shōshi that of "Inner Palatine" ("chūgū"), a toponymically derived equivalent coined for the occasion".She went on to hold the title(s) of Empress Dowager ("Kōtaigō") and Grand Empress Dowager ("Taikōtaigō").