Georgios Aggelopoulos was born in Dimitsana, Arcadia prefecture in 1746 to poor parents. A studious child, Georgios attended school at Dimitsana before continuing his education in Athens for two years. With the help of his uncle he continued his education in the theological school at Smyrna for another five years. Having been raised in the hesychastic environment around the Monastery of Philosophou he turned to a monastic life and was tonsured a monk in Strophades with the name Gregory. He continued his education in theology and philosophy at the School of Patmos.
After completing his education at Patmos, Gregory returned to Smyrna where he was ordained a deacon in 1775 by Metr. Procopius of Smyrna and subsequently became an archdeacon. Over the following years he was ordained a priest and a protosyncelos [Chancellor]. In 1785, he was elected by the Patriarch of Constantinople to the position of Bishop of the Metropolis of Smyrna succeeding Procopius who had become Patriarch of Constantinople.
[Konstantinos Koumas offers that St. Gregory was not only "pure in ethos, spartan in diet, arrayed in humility, zealous for the faith, dedicated to all of his works", but he was "adamant for his ideas and was never swayed by any foe, once he had made his decision." (http://www.synaxarion.gr/gr/sid/2613/sxsaintinfo.aspx)]
In what was becoming a volatile political atmosphere, Gregory was elected to the patriarchal throne of Constantinople in May 1797. In a year he was deposed and deported to the Monastery of Iviron on Mount Athos where he lived an ascetic life of study. On September 23, 1806, the synod recalled him to the patriarchal see. With the shifting Turkish politics and the revolt of the Genitsars, Gregory’s second stint as patriarch ended in 1810 when he was expelled first to Pringiponisos, and then again to Mount Athos, where he stayed for nine years. On December 15, 1818, for the third time Gregory was called to the patriarchal see, this time at a crucial and tense time in the Greek struggle for independence.
In 1818, Gregory became a member of the Filiki Eteria (Friendly Society) that was preparing for a revolt against the Turkish rule. However, when Alexander Ypsilantis crossed the Prut River, starting the Greek revolt in Romania, Gregory felt it necessary to excommunicate him to protect the Greeks of Constantinople from reprisals by the Ottoman Turks.
[The following life of the Saint in Greek includes a quote from Alexander Ypsilantis, where he acknowledges that St. Gregory was doing this under pressure of the Turks, and he praises his sacrifice: http://www.synaxarion.gr/gr/sid/2613/sxsaintinfo.aspx.]
[When during a meeting of the Holy Synod of the Ecumenical Patriarchate, the Metropolitan of Derkon Gregory suggested that the Patriarch move to the Peloponnese to become the head of the Revolution, St. Gregory responded: "And I as the head of the Nation and we as Synod ought to die for the common salvation. Our death will give justification to Christendom to defend the Nation against the tyrant. And if we embolden the Revolution, then we will justify the Sultan in deciding to destroy the whole Nation."
When some tried to convince him to flee Constantinople to save himself, the good shepherd responded:
"They are trying to get me to flee. A sword will be drawn at the loins of Constantinople and the rest of the cities of Christian eparchies. You wish however that, vested, I take refuge in a ship or be locked in a house and never be a beneficial Ambassador, that I would then hear how the executioners hacked apart the abandoned people. Never! For this I am Patriarch, that I may save my Nation, but never however will they perceive anything other than the faith portrayed on my face. The Greeks, the men of battle, will fight with greater zeal, until they soon will be granted victory; of this I am certain. Look with patience if what I am saying comes true. Today (Palm Sunday) we will eat fish, but after a few days and likely this week the fish will eat us...Yes, why shouldn't I become food for animals, I will never accept fleeing to Odessa, or Kerkyra or Ancyra, passing among people pointing their fingers saying: "Here comes the killer Patriarch." If my Nation is saved and triumphant, then I will accept incense of praise and honors, for I paid my debt...I go wherever my nous, the great people of the Nation and Heavenly Father call me, the martyr of human deeds."
"We are required", he said, "to shepherd our flocks well and to do that which is needed, as Jesus did for us to save us..." (http://www.synaxarion.gr/gr/sid/2613/sxsaintinfo.aspx)]
The reprisals did come during Holy Week in April 1921 after the Greeks revolted in the Peloponnesus. During celebration of the divine liturgy, with eight hierarchs, on the night of Pascha of April 10, Gregory was arrested and, by order of Sultan Mahmud II, hanged on the front gate of the Patriarchate compound in his full Patriarchal vestments. The gate has been closed, locked, and not used since. After hanging for three days and being mocked by the passing crowds, his body was taken down and given to a group of Jews who dragged it through the streets of Constantinople before throwing it into the Bosphorus.
Gregory’s body was recovered from the sea by a Greek seaman, Nicholas Sklavos, and secreted to Odessa, then in Southern Russia, where it was buried with honors at the Church of the Holy Trinity. Later his relics were enshrined in the Metropolitan Cathedral in Athens. His statue, along with that of Rigas Feraios, stands outside the University of Athens as great martyrs of the Greek Revolution."
(taken from: http://orthodoxwiki.org/Gregory_V_of_Constantinople, text in brackets are amateur translations from Greek text here: http://www.synaxarion.gr/gr/sid/2613/sxsaintinfo.aspx)
The final testament of St. Gregory V from the Monastery of Iveron is available here (in Greek): http://radiofloga.blogspot.com/2010/04/blog-post_5427.html.
Apolytikion in the Fourth Tone (amateur translation)
You righteously served the God of all as a priest, and offered yourself to Christ as a chosen sacrifice by struggling well. Wherefore by your hanging, you were truly shone to be a deliver from slavery to the nation of the Greeks, therefore O Hieromartyr Gregory we honor you.
Christ is risen from the dead, by death, trampling down upon death, and to those in the tombs, bestowing life!
Truly the Lord is risen!