More news arrived: Attidius Cornelianus's army had been defeated in battle against the Parthians, and retreated in disarray.
Reinforcements were dispatched for the Parthian frontier.
Publius Julius Geminius Marcianus, an African senator commanding X Gemina at Vindobona (Vienna), left for Cappadocia with detachments from the Danubian legions.
Three full legions were also sent east: I Minervia from Bonn in Upper Germany, II Adiutrix from Aquincum, and V Macedonica from Troesmis.

The northern frontiers were strategically weakened; frontier governors were told to avoid conflict wherever possible.
Attidius Cornelianus himself was replaced by Marcus Annius Libo, Marcus's first cousin.
He was young—his first consulship was in 161, so he was probably in his early thirties—and, as a mere patrician, lacked military experience.
Marcus had chosen a reliable man rather than a talented one.

Marcus took a four-day public holiday at Alsium, a resort town on the Etrurian coast.
He was too anxious to relax.
Writing to Fronto, he declared that he would not speak about his holiday.
Fronto replied ironically: "What?
Do I not know that you went to Alsium with the intention of devoting yourself to games, joking and complete leisure for four whole days?"
He encouraged Marcus to rest, calling on the example of his predecessors (Pius had enjoyed exercise in the palaestra, fishing, and comedy), going so far as to write up a fable about the gods' division of the day between morning and evening—Marcus had apparently been spending most of his evenings on judicial matters instead of at leisure.
Marcus could not take Fronto's advice. "
I have duties hanging over me that can hardly be begged off," he wrote back.
Marcus put on Fronto's voice to chastise himself: "'Much good has my advice done you', you will say."
He had rested, and would rest often, but "—this devotion to duty.
Who knows better than you how demanding it is?"

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".
More news arrived: Attidius Cornelianus's army had been defeated in battle against the Parthians, and retreated in disarray. Reinforcements were dispatched for the Parthian frontier. Publius Julius Geminius Marcianus, an African senator commanding X Gemina at Vindobona (Vienna), left for Cappadocia with detachments from the Danubian legions. Three full legions were also sent east: I Minervia from Bonn in Upper Germany, II Adiutrix from Aquincum, and V Macedonica from Troesmis.
The northern frontiers were strategically weakened; frontier governors were told to avoid conflict wherever possible. Attidius Cornelianus himself was replaced by Marcus Annius Libo, Marcus's first cousin. He was young—his first consulship was in 161, so he was probably in his early thirties—and, as a mere patrician, lacked military experience. Marcus had chosen a reliable man rather than a talented one.
Marcus took a four-day public holiday at Alsium, a resort town on the Etrurian coast. He was too anxious to relax. Writing to Fronto, he declared that he would not speak about his holiday. Fronto replied ironically: "What? Do I not know that you went to Alsium with the intention of devoting yourself to games, joking and complete leisure for four whole days?" He encouraged Marcus to rest, calling on the example of his predecessors (Pius had enjoyed exercise in the palaestra, fishing, and comedy), going so far as to write up a fable about the gods' division of the day between morning and evening—Marcus had apparently been spending most of his evenings on judicial matters instead of at leisure. Marcus could not take Fronto's advice. "I have duties hanging over me that can hardly be begged off," he wrote back. Marcus put on Fronto's voice to chastise himself: "'Much good has my advice done you', you will say." He had rested, and would rest often, but "—this devotion to duty. Who knows better than you how demanding it is?"
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".
Lucius Verus