The retired Emperor (Chiten no kimi) - the form of the succession to the Emperor was in secure form and it was passed on by the male members of the Imperial family, however the position of the retired Emperor itself was abolished.
上皇（治天の君）－天皇の形態は男系での皇位継承を非常に安定させる形態だったが、明治以降、上皇の存在は廃止されている。