In Aquileia, The forerunner of Venice, this city at the head of the Adriatic Sea was destroyed by barbarians in the 5th century. the holy virgin martyrs Euphemia, Dorothea, Thecla, and Erasma. Under the Emperor Nero and the Prefect Sebastus they were grievously tortured and beheaded. They were buried by St. Hermagoras. – Roman Martyrology for September 3
According to the readings in the Office of Saint Euphemia for September 3, there was a wealthy pagan in first-century Aquileia named Valentius. He had four daughters: Euphemia, Dorothea, Thecla, and Erasma. All four were persuaded by their uncle Valentinianus to convert to the Christian faith and be baptized by St. Hermagoras, the first bishop of Aquileia. Later Valentius told Euphemia and Dorothea that he was going to have them married, but they protested that they were dedicated to the Heavenly Spouse. He flew into a rage and threatened them with a sword, so they fled to the home of Valentinianus, who hid them there. Unfortunately, a servant betrayed them to Sebastus the governor. He had all the sisters tortured in hopes they would apostatize, but they did not, so he ordered that they be beheaded.
Valentius himself executed the order and threw the heads and bodies from a high tower into the river below. Suddenly there was an earthquake, and the tower crumbled and caught fire. Valentius died in the flames. That night Valentinianus and Hermagoras went down to the river hoping to find the bodies and heads. A ship appeared laden with the sacred relics, drawn by two tall youths who shone in the night. They gave their charge to the bishop, who then consecrated Valentinianus' house as a church to house the relics.
Several ancient texts make this Euphemia a native of Ravenna who was martyred while visiting Aquileia and whose relics were later returned to Ravenna, something that does not quite fit with the narrative in the office (Acta Sanctorum, September vol. 1, 606).
The four sisters are portrayed in the four pendentives of the South (Leonard) Cupola at St. Mark's Cathedral, Venice. Except for Erasma, each of them shares her name with another more illustrious virgin martyr. Our Euphemia is not Euphemia of Chalcedon, martyr of the 4th century, nor is Dorothea the same person as the well-known St. Dorothy. And this Thecla is not the heroine of the apocryphal Acts of Paul and Thecla.
Prepared in 2016 by Richard Stracke, Emeritus Professor of English, Augusta University