Fronto sent Marcus a selection of reading material, including Cicero's "pro lege Manilia", in which the orator had argued in favor of Pompey taking supreme command in the Mithridatic War. It was an apt reference (Pompey's war had taken him to Armenia), and may have had some impact on the decision to send Lucius to the eastern front. "You will find in it many chapters aptly suited to your present counsels, concerning the choice of army commanders, the interests of allies, the protection of provinces, the discipline of the soldiers, the qualifications required for commanders in the field and elsewhere [...]" To settle his unease over the course of the Parthian War, Fronto wrote Marcus a long and considered letter, full of historical references. In modern editions of Fronto's works, it is labeled "De bello Parthico" ("On the Parthian War"). There had been reverses in Rome's past, Fronto writes, at Allia, at Caudium, at Cannae, at Numantia, Cirta, and Carrhae; under Trajan, Hadrian, and Pius; but, in the end, Romans had always prevailed over their enemies: "always and everywhere [Mars] has changed our troubles into successes and our terrors into triumphs".