Augustus also promoted the ideal of a superior Roman civilization with a task of ruling the world (to the extent to which the Romans knew it), a sentiment embodied in words that the contemporary poet Virgil attributes to a legendary ancestor of Augustus: "tu regere imperio populos, Romane, memento"—"Roman, remember by your strength to rule the Earth's peoples!" The impulse for expansionism was apparently prominent among all classes at Rome, and it is accorded divine sanction by Virgil's Jupiter in Book 1 of the "Aeneid", where Jupiter promises Rome "imperium sine fine", "sovereignty without end".