Over the winter of 161–62, as more troubling news arrived—a rebellion was brewing in Syria—it was decided that Lucius should direct the Parthian War in person.
He was stronger and healthier than Marcus, the argument went, more suited to military activity.
Lucius's biographer suggests ulterior motives: to restrain Lucius's debaucheries, to make him thrifty, to reform his morals by the terror of war, to realize that he was an emperor.
Whatever the case, the senate gave its assent, and Lucius left.
Marcus remained in Rome; the city "demanded the presence of an emperor".

Furius Victorinus, one of the two praetorian prefects, was sent with Lucius, as were a pair of senators, M. Pontius Laelianus Larcius Sabinus and M. Iallius Bassus, and part of the praetorian guard.
Victorinus had previously served as procurator of Galatia, giving him some experience with eastern affairs.
Moreover, he was far more qualified than his praetorian partner, Cornelius Repentinus, who was said to owe his office to the influence of Pius's mistress, Galeria Lysistrate.
Repentinus had the rank of a senator, but no real access to senatorial circles—his was merely a decorative title.
Since a prefect had to accompany the guard, Victorinus was the clear choice.

Laelianus had been governor of both Pannonias and Governor of Syria in 153; thus he had first-hand knowledge of the eastern army and military strategy on the frontiers.
He was made comes Augustorum ("companion of the emperors") for his service.
Laelianus was, in the words of Fronto, "a serious man and an old-fashioned disciplinarian".
Bassus had been Governor of Lower Moesia, and was also made comes.
Lucius selected his favorite freedmen, including Geminus, Agaclytus, Coedes, Eclectus, and Nicomedes, who gave up his duties as praefectus vehiculorum to run the commissariat of the expeditionary force.
The fleet of Misenum was charged with transporting the Emperor and general communications and transport.

Lucius left in the summer of 162 to take a ship from Brundisium; Marcus followed him as far as Capua.
Lucius feasted himself in the country houses along his route, and hunted at Apulia.
He fell ill at Canosa, probably afflicted with a stroke, and took to bed.
Marcus made prayers to the gods for his safety in front of the senate, and hurried south to see him.
Fronto was upset at the news, but was reassured when Lucius sent him a letter describing his treatment and recovery.
In his reply, Fronto urged his pupil to moderate his desires, and recommended a few days of quiet bedrest.
Lucius was better after three days' fasting and a bloodletting.
It was probably only a mild stroke.

Verus continued eastward via Corinth and Athens, accompanied by musicians and singers as if in a royal progress.
At Athens he stayed with Herodes Atticus, and joined the Eleusinian Mysteries.
During sacrifice, a falling star was observed in the sky, shooting west to east.
He stopped in Ephesus, where he is attested at the estate of the local aristocrat Publius Vedius Antoninus, and made an unexpected stopover at Erythrae.
The journey continued by ship through the Aegean and the southern coasts of Asia Minor, lingering in the famed pleasure resorts of Pamphylia and Cilicia, before arriving in Antioch.
It is not known how long Verus's journey east took; he might not have arrived in Antioch until after 162.
Statius Priscus, meanwhile, must have already arrived in Cappadocia; he would earn fame in 163 for successful generalship.
Over the winter of 161–62, as more troubling news arrived—a rebellion was brewing in Syria—it was decided that Lucius should direct the Parthian War in person. He was stronger and healthier than Marcus, the argument went, more suited to military activity. Lucius's biographer suggests ulterior motives: to restrain Lucius's debaucheries, to make him thrifty, to reform his morals by the terror of war, to realize that he was an emperor. Whatever the case, the senate gave its assent, and Lucius left. Marcus remained in Rome; the city "demanded the presence of an emperor".
Furius Victorinus, one of the two praetorian prefects, was sent with Lucius, as were a pair of senators, M. Pontius Laelianus Larcius Sabinus and M. Iallius Bassus, and part of the praetorian guard. Victorinus had previously served as procurator of Galatia, giving him some experience with eastern affairs. Moreover, he was far more qualified than his praetorian partner, Cornelius Repentinus, who was said to owe his office to the influence of Pius's mistress, Galeria Lysistrate. Repentinus had the rank of a senator, but no real access to senatorial circles—his was merely a decorative title. Since a prefect had to accompany the guard, Victorinus was the clear choice.
Laelianus had been governor of both Pannonias and Governor of Syria in 153; thus he had first-hand knowledge of the eastern army and military strategy on the frontiers. He was made comes Augustorum ("companion of the emperors") for his service. Laelianus was, in the words of Fronto, "a serious man and an old-fashioned disciplinarian". Bassus had been Governor of Lower Moesia, and was also made comes. Lucius selected his favorite freedmen, including Geminus, Agaclytus, Coedes, Eclectus, and Nicomedes, who gave up his duties as praefectus vehiculorum to run the commissariat of the expeditionary force. The fleet of Misenum was charged with transporting the Emperor and general communications and transport.
Lucius left in the summer of 162 to take a ship from Brundisium; Marcus followed him as far as Capua. Lucius feasted himself in the country houses along his route, and hunted at Apulia. He fell ill at Canosa, probably afflicted with a stroke, and took to bed. Marcus made prayers to the gods for his safety in front of the senate, and hurried south to see him. Fronto was upset at the news, but was reassured when Lucius sent him a letter describing his treatment and recovery. In his reply, Fronto urged his pupil to moderate his desires, and recommended a few days of quiet bedrest. Lucius was better after three days' fasting and a bloodletting. It was probably only a mild stroke.
Verus continued eastward via Corinth and Athens, accompanied by musicians and singers as if in a royal progress. At Athens he stayed with Herodes Atticus, and joined the Eleusinian Mysteries. During sacrifice, a falling star was observed in the sky, shooting west to east. He stopped in Ephesus, where he is attested at the estate of the local aristocrat Publius Vedius Antoninus, and made an unexpected stopover at Erythrae. The journey continued by ship through the Aegean and the southern coasts of Asia Minor, lingering in the famed pleasure resorts of Pamphylia and Cilicia, before arriving in Antioch. It is not known how long Verus's journey east took; he might not have arrived in Antioch until after 162. Statius Priscus, meanwhile, must have already arrived in Cappadocia; he would earn fame in 163 for successful generalship.
Lucius Verus