The Aeneid
The text, and the Purcell opera are alluding to the Roman legend of the Aeneid, the story of a Trojan Warrior Aeneas, seeking Italy in order to settle there and secure his son's lineage. Aeneas is blown off course from Sicily, and lands on the shores of Northern Africa, in Carthage, a recently settled city of former Tyrians. Their queen is Dido, with whom Aeneas has a love affair, before departing for Italy and leaving Dido alone. She becomes so distraught that she orders for a large pyre to be placed, on which she plans to impale herself, and be set ablaze so that Aeneas will see from his ship. This is perhaps the most poignant part of the legend, and ends at the culmination of Book IV.
Read more about this topic: Dido's Lament