だんのうらノ浦の合戦 がっせんだったら
danno urano gassendattara

Noun
Da Copula

The "-tara" conditional form ("if/when…") of 壇ノ浦の合戦

1. If/When the Battle of Dan-no-ura…; Had the Battle of Dan-no-ura happened…

Tara Conditional