The muse for the song comes from the Greek myth of Dido and Aeneas.
During the Trojan War Aeneas’s town was destroyed and he had to leave with the rest of the Trojans to escape.
As it goes, he went in search of his destiny. That is when he met Dido, the queen of Carthage.
After Aeneas and Dido fell in love, Jupiter convinced Aeneas to leave Dido. He did this so Aeneas would continue on his journey to found Rome.
Aeneas went to Dido to tell her that he was leaving, Dido became distraught, losing her mind, unable to deal with the news the love of her life was following Jupiter's command and leaving.
Incapable of facing life without Aeneas, she set a curse of fire, war and death on the Romans, before uttering her final words "Let the Tempest be my grace" and killing herself with the sword he had left behind.