Latin was the language of the Romans from the earliest known period. Writing under the first Roman emperor Augustus, Virgil emphasizes that Latin was a source of Roman unity and tradition. In Virgil's epic "Aeneid" about the founding of Rome, the supreme deity Jupiter dictates that the refugee Trojans who have come to settle in Italy will use the language of the native Latini as a means of unification: "they will keep the speech "(sermo)" and "mores" of their fathers ... and I will make them all Latins with one mode of expression" "(uno ore," literally "with one mouth"). The Julio-Claudian emperors, who claimed descent from the Virgilian hero Aeneas, encouraged high standards of correct Latin "(Latinitas)", a linguistic movement identified in modern terms as Classical Latin, and favored Latin for conducting official business.