MANUELE I COMMENO, emperor of BYZANTIUM. — Son of Giovanni Comneno and Piriska (Irene), a Hungarian princess; he ruled the empire from 1143 to 1180. The ideal of restoring the universal Empire, which directed his policy of intervention in Italy, first against the Normans (1143–58), then against Barbarossa, in Hungary, in Anatolia against the sultan of Iconium, and in Syria against Nūr ed-Dīn in protection of the Frankish colonies, also inspired his repeated attempts at religious union with Rome and with the Churches of Armenia and Syria.
The conflicts that arose between the papacy and F. Barbarossa led M. to hope that he might replace the German Emperor as protector of the Holy See; he offered his support to Adrian IV, and in 1166 he proposed to his successor Alexander III a union with the Greek Church, provided that he was recognized as the sole emperor. Although the Pope declared that he could not accept these proposals, his relations with M. remained good, and in 1176, at Anagni, M. appears among the allies of the Holy See.
In the East, the consolidation of Byzantine rule led to negotiations for union with Nerses, katholikos of the Armenians. In May 1170 theological conferences took place, also attended by a delegate of the celebrated patriarch of Antioch, Michael the Syrian. The declared opposition of the Armenian clergy rendered these negotiations fruitless, as it did those undertaken later (1175, 1177, 79), under the katholikos Gregory IV Dpha (1173–93).
M. took an active part in the numerous theological discussions that took place within the Byzantine Church. He promoted the condemnation of the monk Niphon, accused of Bogomilism but protected by the patriarch Kosmas (1146–47). Demetrius of Lampe was also condemned, for misinterpreting Christ’s words, « the Father is greater than I », as were Soterichos Panteugenes and others who maintained that the Eucharistic sacrifice is offered only to the Father and the Holy Spirit. Finally, M. had to face strong opposition from the Byzantine clergy for having sought to suppress an anathema customarily recited by Muslims who converted to Christianity, and which could offend their susceptibilities.