島津 しまず侵入 しんにゅう事件 じけんだったら
shimazu shinnyūjikendattara

Noun
Da Copula

The "-tara" conditional form ("if/when…") of 島津侵入事件

1. If the Shimazu invasion incident…; Had the Shimazu invasion incident happened…; Were the Shimazu invasion incident to happen…

Tara Conditional