Seiwa
Seiwa is a term that appears in Japanese history in several related contexts. It is most commonly associated with Emperor Seiwa, who is traditionally counted as the 56th emperor of Japan and who reigned during the Heian period in the 9th century. Details of his personal life are limited in early sources, but his name became linked to the imperial line of that era.
The Seiwa era (858–875) is another use of the name. This was a nengō, or era name,
Seiwa Genji refers to a major branch of the Minamoto clan that traces its lineage to Emperor
In summary, Seiwa can denote (1) Emperor Seiwa, a 9th‑century emperor of the Heian period; (2) the