They were often called female Emperor (they were also called Jotei in Goon and Nyotai in Karagoe), after there was active argument of the issue of Imperial succession since 2004, they were commonly called female Emperor in an official document or in the publication.
古くから女帝（呉音じょてい、漢音にょたい）と呼ばれることが多かったが、皇位継承問題の議論が盛んとなった2004年以降、日本の公文書や報道等では女性天皇の表現が用いられるようになった。