Early Life and Monasticism
According to the account preserved in the Mystagogy/Sanidopoulos source, Theodosia was born in Constantinople to devout parents who had prayed for her birth, during the reign of Emperor Theodosios of Atramyttion (715–717). Her father died when she was seven, after which her mother placed her in the women's Monastery of the Holy Martyr Anastasia in Constantinople.
When her mother also died, Theodosia inherited a substantial fortune. She used part of it to commission three icons of gold and silver — depicting Christ, the Theotokos, and Saint Anastasia — and distributed the remainder to the poor and orphaned before taking monastic vows.
The Chalke Gate Icon and the Outbreak of Iconoclasm
The icon of Christ displayed above the main entrance of the Chalke Gate — the ceremonial gateway of the imperial palace — was one of Constantinople's most prominent religious symbols. When Emperor Leo III the Isaurian (717–741) deposed the iconophile Patriarch Germanos and enacted iconoclastic decrees, he ordered the removal and destruction of this icon.
According to the sources, its removal was both a major political statement and a spark for violent rioting in the city, marking the beginning of the official prohibition of icons in the Empire. As an imperial guard (spatharios) attempted to strike the icon down with an axe, Theodosia led a group of pious women who pulled down the ladder, causing the guard to fall to his death.
The Wikipedia account dates this confrontation to 19 January 729. The other women then proceeded to the patriarchate and threw stones at the iconoclast Patriarch Anastasius; all of them except Theodosia were immediately beheaded.
Martyrdom
Theodosia was seized by an executioner who dragged her to the Forum of the Ox (Forum Bovis). There, according to the sources, a horn was driven through her throat, and she received her martyrdom. The Wikipedia account describes her execution as having a ram's horn hammered through her neck.
Relics & Shrines
After iconoclasm was overcome at the Triumph of Orthodoxy, Theodosia's remains were venerated. The Mystagogy source states they were enshrined at the Monastery of Dexiokratous, where numerous miracles were reportedly performed.
The Wikipedia account records that her body was venerated in the church of Hagia Euphemia en to Petrio, which was subsequently renamed after her. A gate in Constantinople's sea walls — the Gate of Hagia Theodosia (Turkish: Ayakapı) — was also named after her church. Saint Nikodemos the Hagiorite later composed a Divine Office in her honor.
Legacy and Iconography
Theodosia became emblematic of resistance to iconoclasm. An icon celebrating the Triumph of Orthodoxy depicts her as an iconodule martyr carrying the icon of Christ Chalkites, symbolizing the defense of the holy images.
The icon of Christ above the Chalke Gate that she died defending had a contested history through the iconoclast period: around 787 the Empress Irene reinstated it, Leo V removed it again between 813 and 820, and after 843 the artist Lazaros created a mosaic replacement.
Commemoration
Theodosia is commemorated in the Eastern Orthodox and Eastern Catholic traditions on May 29, the date to which her feast was transferred. The Roman Catholic Church keeps her on July 18, which the sources identify as the original date. She is invoked especially by the infirm.
She is distinct from Saint Theodosia of Tyre, who is also commemorated on May 29.
