Princess Piroska of Hungary was the daughter of King Ladislaus I the Saint, Szent Laszlo or Saint Ladislaus of Hungary. She married Byzantine Emperor John II Commenus, and she became a saint of the Greek Orthodox Church. Piroska as you know comes from piros, the Hungarian word for "red," and it is a diminutive meaning "little red one," and the red colour was regarded by the Magyars as something very beautiful and rich. But Piroska is probably a pagan Hungarian name, that with Christianity was associated with the Latin name Prisca (Saint Prisca or Priscilla was a Roman martyr of the third century). Princess Piroska was forced against her will to marry John Commenus by her uncle King Kalman (Koloman), a marriage carried out in the interests of the state. When Princess Piroska of Hungary went to live to the imperial court at Constantinople, she became Christian Orthodox and adopted the name Irene, and so she is known as Saint Irene Prisca by the Greek Orthodox Church, canonized due to her piety. She co-founded with her husband in Constantinople the monastery and church of Saint Saviour Pantocrator, where she is buried. She never turned her back on those who were in need, and she attended the needs of Hungarian pilgrims returning from the Holy Land who stopped in Constantinople on their way back home. Her portrait together with those of her husband and son, the future Emperor Manuel I Commenus, are in a mosaic in the basilica of Hagia Sophia or Saint Sophia in Constantinople. My opinion is that even though she is not a Catholic saint but a Greek Orthodox, it is right for Hungarians to regard her as a saint too, and thus to be revered as Saint Piroska, for her Christian virtues defined her sainthood, and because she was Magyar. The source of the picture of Szent Piroska is: Kings & Queens of Hungary – Princes of Transylvania (Hungary: Corvina, 2000), 6. In this book the photo is described as: "Ladislas' daughter, Piroska, who later became empress Eiréné of Byzantium. Mosaic from the Hagia Sophia."

But besides the Hungarian Princess and Byzantine Empress Saint Irene Prisca (Piroska) of the Greek Orthodox Church, the saint for the name Piroska in the Catholic Church would be Saint Prisca, the Roman martyr. This would not be odd, for another case of a pagan Hungarian name that became associated with an originally unrelated Christian and Latin name is Gyula. When Christianity took root in Hungary, the pagan name Gyula became associated with the name Julius, thus the name's day in the Church for Gyula would be the feast of Saint Julius. The name's day for those named Piroska can be celebrated in the feast of Saint Prisca. Szent Piroska's feast in the Greek Orthodox Church, where she is known as Saint Irene or Xenia, is August 13, the day she died. Saint Prisca's (in Hungary Piroska) details are in: