“Regret” (1887) by Miguel Navarro Cañizares (c. 1835 – 23 October 1913), image from Wikimedia, assumed allowed under Fair Use.
The Manufacture of Gunpowder
Image from The Goya Foundation, assumed allowed under Fair Use. Painting “The Manufacture of Gunpowder” by Francisco José de Goya y Lucientes, or just Goya (1746-1828). Goya should have his own website.
Army Of Angels
Image from somewhere on the web, assumed allowed under Fair Use. Painting of angels by Guariento di Arpo (1310-1370).
Ascension of Christ
Image from Wikimedia, assumed allowed under Fair Use. Painting of angel by Guariento di Arpo (1310-1370).
Penultimate Guariento
Image from somewhere on the web, assumed allowed under Fair Use. Painting of angel by Guariento di Arpo (1310-1370).
Angelo di guariento 1, 1357
Image from Wikimedia, assumed allowed under Fair Use. Painting of angel by Guariento di Arpo (1310-1370).
Guariento 001
Image from Wikimedia, assumed allowed under Fair Use. Painting of angel by Guariento di Arpo (1310-1370).
Angelo di guariento 2
Image from Wikimedia, assumed allowed under Fair Use. Painting of angel by Guariento di Arpo (1310-1370).
Angelo di Guariento 3
Image from Wikimedia, assumed allowed under Fair Use. Painting of angel by Guariento di Arpo (1310-1370).
Guariento 003
Image from Wikimedia, assumed allowed under Fair Use. Painting of angel by Guariento di Arpo (1310-1370).
Guariento 002
Image from Wikimedia, assumed allowed under Fair Use. Painting of angel by Guariento di Arpo (1310-1370).
Painting of Archangel Saint Michael by Guariento
Image from Wikimedia, assumed allowed under Fair Use. Painting of Saint Michael by Guariento di Arpo (1310-1370).
Calling of Peter and Andrew
Image from Wikimedia, assumed allowed under Fair Use. Painting of calling Peter and Andrew by Duccio di Buoninsegna (c. 1255–1260 – c. 1318–1319), aka “The Duce”.
Ancient Woman Praying
Ancient woman praying, painting in Catacomb of Callixtus, 2nd-4th century, file found on Wikimedia, assumed allowed under Fair Use.
Angel of the Last Judgment
Angel of the Last Judgement, 11th century, abbey of Sant’Angelo in Formis, assumed allowed under Fair Use.
Seven Of Nine Images
Theophilus Makes A Deal With The Devil
Image from Wikipedia, assumed allowed under Fair Use. Illustration of Theophilus of Adana making a deal with the devil to attain power, from the Maastricht Hours, early 14th century.
Transfiguration By The Duce
Image from Wikimedia, assumed allowed under Fair Use. Painting of the Transfiguration by Duccio di Buoninsegna (c. 1255–1260 – c. 1318–1319), aka “The Duce”.
Rejection of Joachim’s Sacrifice
Painting of Rejection of Joachim’s Sacrifice by Giotto di Bondone (1267 – 1337), at his website. I actually got the image file from somewhere else, but his site has a page about it. Assumed allowed under Fair Use.
Nativity By Guido of Siena
Painting of the Nativity by Guido of Siena (13th Century), assumed allowed under Fair Use.
Meister der Legende der Heiligen Cecilia
Painting by Meister der Legende der Heiligen Cecilia, circa 1300. Image from 
German Painting of the Last Judgement
German painting from about 1518 in a museum in Austria. (Hey, Austrians do not complain when people assume Hitler was German, so I can get the painting’s origin wrong.) Image from Wikimedia, assumed allowed under Fair Use.
The Annunciation By The Duce
Image from Wikimedia, assumed allowed under Fair Use. Painting of the Annunciation by Duccio di Buoninsegna (c. 1255–1260 – c. 1318–1319), aka “The Duce”. Finally, this site takes a Duce.
Radha Pining for Her Beloved
“Radha Pining for Her Beloved”, 1634, at the Brooklyn Museum, assumed allowed under Fair Use.
The Purification of the Temple by El Greco 1571
“The Purification of the Temple” by El Greco (1541 – 7 April 1614), at the El Greco Foundation site, assumed allowed under Fair Use.