ORESTES, Patriarch of JERUSALEM. — A Greek monk, born probably in Calabria about the middle of the 9th century, when Sicily had already been conquered by the Arabs and, as a consequence, the Greek Basilian monks from there had fled to Calabria. The circumstances of his death are unclear: while some speak of his death in exile in Babylon in 1012, others, perhaps more plausibly, assign the year 1005 and Constantinople as the place of his death.
O. wrote three Greek biographies of Calabrian monks: of SABA the Younger, of his father CHRISTOPHER, and of his brother MACARIUS. He also composed hymns, as is evident from the Corsinian Codex 366. Having become Greek Patriarch of Jerusalem around 984, he enjoyed the trust of the Greek Emperor BASIL II and of the Caliph al-‘Azīz, who had married his sister. He was chosen as a mediator of peace between the Byzantines and the Arabs and succeeded in this role (1000–1001). In Constantinople, where he was staying during the peace negotiations, he probably remained for several years, while his brother ARSENIUS administered the patriarchate of Jerusalem.