弘仁 こうにん貞観 じょうがん時代 じだいであれば
kō ninjōganjidaideareba

Noun
Da Copula

The "-eba" conditional form ("if/when…") of 弘仁貞観時代

1. If it were the Koken/Tempyo era.; If it had been the Koken/Tempyo era.

Ba Conditional