c.396-457. Eastern emperor from 450. An obscure retired tribune who became part of the dynasty through a marriage in form only with the virgin Pulcheria,* an ardently Nicene Christian and sister of the deceased Theodosius II. Marcian was persuaded by her and Leo I of Rome into calling the 451 Council of Chalcedon.* One result was the imperial espousal of the orthodox Definition. Marcian's reign saw also the termination of the raiding activities of the Huns under Attila.*