Hieromonk Parthenios Partheniades was a member of the Kollyvades movement, and when he was forced to leave Mount Athos he went to the Monastery of the Annunciation in Icarus. In 1798 Parthenios arrived at the island of Patmos, accompanied by several other monks, and established what is today known as the Kathisma of Parthenios.
Needing further resources to complete construction of the monastery, Parthenios went to Thrace to raise the funds. In Didymoteicho, Thrace he served as a priest. Until 1804 the public market had been open on Saturday, but the Turks transferred it to Sunday, moving the Greeks to protest. Parthenios, who was staying at the Monastery of Zoodochos Pege, reacted strongly against this unjust and hypocritical decision of the Turkish governor, by denouncing it publicly in the church, causing the Muslims to take notice.
One day he also advised a young Christian woman how to flee a relationship she had with a Muslim Turk. When this Muslim learned of it, he became enraged and shot Parthenios dead at the entrance to the Metropolitan Church of Saint Athanasios on Sunday the 5th of March in 1805, after having served the Divine Liturgy. The Christians then buried his head next to the Church of Saint Athanasios, while his body was buried separately.
The current Metropolitan Church of Saint Athanasios, located in the castle, replaced the old one in 1834. It should also be noted that in 1520 the Venerable Martyr James of Kastoria was also martyred nearby by hanging.
