How did emperor Marcus Aurelius become emperor?

Answer 1

In 137, Hadrian had announced that his eventual successor would be Lucius Ceionius Commodus, renamed L. Aelius Caesar. Marcus had already attracted the attention of Hadrian (who had nicknamed him verissimus, which translates as "truest") and had been made a member of the equestrian order when he was six; he was subsequently engaged to Ceionia Fabia, Commodus' daughter. The engagement, however, was annulled later after the death of Commodus, as Marcus was betrothed to Antoninus' daughter. Therefore, on the death of Hadrian's first adopted son L. Aelius Verus, Hadrian made it a precondition of making Antoninus his successor that Antoninus would adopt Marcus (then called Marcus Aelius Aurelius Verus) and Lucius Ceionius Commodus (Lucius Aelius' son, ten years junior than Marcus, renamed Lucius Aurelius Verus), and arrange for them to be next in the line. This Antoninus did, adopting and designating them as his successors on February 25, 138, when Marcus was only seventeen years of age. He would become emperor at 40. It has been suggested that Commodus and Antoninus Pius were designed by Hadrian only as "place warmers" for the young Marcus and Verus. Marcus received an education from some of the greatest scholars of his day: Euphorion for literature, Geminus for drama, Andron for geometry, Caninius Celer and Herodes Atticus in Greek oratory, Alexander of Cotiaeum for Greek, and Marcus Cornelius Fronto for Latin. It is through Marcus' correspondence with Fronto that we have many of the details of his life during the reign of Antoninus. Through these letters Marcus appears as an intelligent, serious-minded and hardworking youth. They also show the growing importance of philosophy for the future emperor: showing impatience for the unending exercises with Greek and Latin declamations, he later became fond of the Diatribai ("Discourses") of Epictetus, an important moral philosopher of the Stoic school. Marcus also started to have an increasing public role at the side of Antoninus, holding the place of consul in 140, 145 and 161 and increasing collaboration in decisions. In 147 he received the proconsular imperium outside Rome and the tribunicia potestas, the main formal powers of emperorship.