Translation of "Mergulhada" in English

Invadem a cidade mergulhada / na embriaguez e no sono; as sentinelas / são massacradas e, uma vez abertos / os portões, os demais guerreiros entram, / conforme o combinado se agrupando.

Now, stealing forward, on the town they fall, / buried in wine and sleep, the guards o'erbear, / and ope the gates; their comrades at the call / pour in and, joining bands, all muster by the wall.