Dido when she first came to Libya had bought the ground to build her
city. Now Iarbas wished to have Dido for his wife, and he had asked
her to marry him, but she had refused. Great was his anger, therefore,
when he heard that the Trojan chief had been received and honored
in Carthage and that a marriage between him and the queen was talked
of as a certain thing. So he went to the temple of his father Jupiter,
and complained bitterly of the conduct of Dido in rejecting himself
and taking a foreign prince into her kingdom to be its ruler. The king
of heaven, naturally enough sympathising with his son, gave ear to his
complaint and he forthwith dispatched Mercury with a message to
AEneas, bidding him to depart instantly from Carthage. This command
the swift-winged god, having sped down from Olympus, and sought out
the Trojan hero, delivered in impressive words.

"All powerful Jove
Who sways the world below and heaven above,
Has sent me down with this severe command:
What means thy lingering in the Libyan land?
If glory cannot move a mind so mean,
Nor future praise from flitting pleasure wean,
Regard the fortunes of thy rising heir:
The promised crown let young Ascanius wear,
To whom the Ausonian sceptre, and the state
Of Rome's imperial name, is owed by fate."
DRYDEN, _AEneid_, BOOK IV.

The command filled AEneas with astonishment and fear. He knew that he
must obey, but how could he break the intelligence to Dido, or what
excuse could he offer for so sudden a departure?