In Händel's Giulio Cesare in Egitto, the libretto to Cleopatra's famous aria reads:
E pur così in un giorno
perdo fasti e grandezze? Ahi fato rio!
Cesare, il mio bel nume, è forse estinto;
Cornelia e Sesto inermi son, né sanno
darmi soccorso. O dio!
Non resta alcuna speme al viver mio.
Piangerò la sorte mia,
sì crudele e tanto ria,
finché vita in petto avrò.
Ma poi morta d'ogn'intorno
il tiranno e notte e giorno
fatta spettro agiterò.
The opera was written during the baroque period at the end of the 18th century, but I'm assuming the libretto is older, though not very much older. The author of the libretto is Nicola Francesco Haym, who based them on a libretto by Giacomo Francesco Bussani, whose text was used no earlier than 1676. Am I assuming wrongly that this is unlikely to still be old Italian? What, then, is the Italian of this era called and what is the appropriate translation for the phrase? The translations I have seen (French, English, and German) simply do not translate the phrase.