Roman emperor, named originally Marcus Annius Verus. He was a nephew of Faustina, the wife of Antoninus Pius, who adopted him. Marcus married Antoninus’ daughter, another Faustina. From youth he was a diligent student and a zealous Stoic. With his adoptive brother, Lucius Verus, as colleague, Marcus succeeded Antoninus in 161. Verus allowed him to dominate, and from 169 Marcus was sole emperor.