The 111th patriarch of the See of Saint Mark (1862-1870). Formerly abbot of DAYR ANBA MAQAR, he was elected in 1862. In 1867, the year that saw the establishment of the first Protestant church by the missionaries in Asyut, he made a tour of Upper Egypt to rally the Coptic flock round the Mother Church. In 1869 he attended the inauguration ceremony of the Suez Canal and had an audience with Sultan ‘Abd-al-‘Aziz. The sultan donated some farmland to the Coptic church, the proceeds of which Demetrius used to finance Coptic schools and other charities. He died on the eve of the Epiphany of 1870, after occupying Saint Mark’s throne for seven years, seven months, and seven days.
After his death, the patriarchate remained vacant for four years because of indecision in the Holy Synod about a worthy successor. During that period, the archbishop of Alexandria, Anba Murqus, was nominated as vice-patriarch to run the church until a successor was elected in the person of CYRIL V.