Justinian saw the orthodoxy of his empire threatened by diverging religious currents, especially Monophysitism, which had many adherents in the eastern provinces of Syria and Egypt. Monophysite doctrine, which maintains that Jesus Christ had one divine nature rather than a synthesis of divine and human nature, had been condemned as a heresy by the Council of Chalcedon in 451, and the tolerant policies towards Monophysitism of Zeno and Anastasius I had been a source of tension in the relationship with the bishops of Rome. Justin reversed this trend and confirmed the Chalcedonian doctrine, openly condemning the Monophysites. Justinian, who continued this policy, tried to impose religious unity on his subjects by forcing them to accept doctrinal compromises that might appeal to all parties, a policy that proved unsuccessful as he satisfied none of them.