Stained Glass Windows

North Aisle, St. Peter's Cathedral, Regensburg, Germany

I have been able to identify only a few of the saints portrayed in the 14 panels shown here. On the left, counting from the top:
Panel #1 is either the deacon St. Vincent or the bishop St. Quirinus. Each was tossed into water with a millstone on his neck: Vincent from a boat into the Mediterranean, Quirinus from the shore of the River Sava. The saint shown here is young and has no mitre, so he could be Vincent.
Panel #2 has two torturers pouring boiling oil onto a saint who is fixed to a wheel. This is most likely St. Quentin, who suffered the boiling oil while being tortured on a rack.
Panel #3 is inscribed SCA APOLLONIA. The man on the left has in his right hand an implement that could be the tooth extractor that is St. Apollonia's attribute.
Panel #6 shows two men beating a female saint who has been stripped to the waist. Almost all of the martrydom stories involve beatings, but it is typical of pictures of the beating of St. Barbara that she be stripped precisely to the waist and beaten by two men with raised arms on either side of her.

Now, on the right side, counting from the top:
Panel #1: A female saint calmly prays from within a circle of fire. She could be Eulalia, Euphemia, or Thecla.
Panel #5: An executioner dispatches a female saint with a knife to the throat or breast. The angle of attack and the presence of a second executioner attacking from behind are most like images of the martyrdom of St. Justina of Padua.

Read more about St. Vincent of Saragossa, St. Quentin, St. Quirinus, St. Eulalia, St. Euphemia, and St. Thecla

Read more about St. Apollonia, St. Justina of Padua, and St. Barbara.

Photographed at the cathedral by Richard Stracke, shared under Attribution-NonCommercial-ShareAlike license.