The Ehsadai period was a time in Rihannsu history after their settlement of ch'Rihan.

Buildings of this era were noted for their classical and elegant construction at a time when the early Romulans were still taming the Two Worlds. One such structure was present at the capital of Ra'tleihfi which was actually earlier than the Ehsadai period as it was actuallymade after the fall of the Ruling Queen Vriha T'Rehu. (TOS novel: Swordhunt)