Dionysius I of Constantinople

Dionysius I was Ecumenical Patriarch of Constantinople in the second half of the fifteenth century, occupying the throne in two separate periods after the Ottoman conquest of the city. He was born in Dimitsana, in the Peloponnese, then still under the Byzantine Despotate of the Morea. No reliable source preserves an exact year of birth. He took monastic vows and went to Constantinople, where he entered the monastery of Magganon and became a disciple of Mark Eugenikos, Metropolitan of Ephesus, the leading Greek opponent of the Union of Florence. Mark ordained him deacon and priest. Dionysius later served as ecclesiarch of the Church of the Pammakaristos, which after 1453 housed the patriarchate once Hagia Sophia had been converted into a mosque.

In the mid-1450s Patriarch Gennadius II Scholarius appointed him Metropolitan of Philippopolis in Thrace. While he held that see he was captured in an Ottoman raid in the early 1460s, sold into slavery, and afterwards ransomed. The patriarchate in these decades was bound up with Ottoman court politics: each new patriarch was expected to pay a peshkesh to the sultan, and rival Greek factions promoted competing candidates. In 1466 Dionysius was raised to the ecumenical throne through the intervention of Mara Branković, daughter of the Serbian despot Đurađ Branković and stepmother of Sultan Mehmed II. Mara, a Christian of substantial influence in the Ottoman palace, backed him against the faction associated with Symeon of Trebizond.

His first patriarchate lasted from 1466 to 1471 and was contested from the start by the same Trapezuntine party that had opposed his election. Opponents accused him of having apostatized to Islam during his earlier captivity and of having been circumcised. Near-contemporary accounts of the patriarchate relate that he submitted to a physical examination before the synod, which showed the charge to be false. Political pressure nonetheless prevailed, and he was deposed in 1471. Symeon of Trebizond returned to the throne. Dionysius withdrew to the Monastery of Eikosiphoinissa, also known as Cosinitza, on Mount Pangaion in Macedonia, and remained there as a monk for many years.

In 1488 he was recalled to Constantinople and restored as patriarch for a second term. After about two years he resigned of his own accord in 1490 and again retired to Eikosiphoinissa. He died at that monastery in 1492 and was buried there. The Eastern Orthodox Church venerates him as a saint and keeps his feast on 23 November. Surviving evidence does not record a wife or children, which accords with a career spent from youth in the monastic state and, later, in the episcopate, both of which required celibacy in the Orthodox Church of his time. Standard hagiographical lists do not attach a specific set of patronages to his name.