Via the superb Public Domain Review. I love this image of the archangel Metatron, taken from the Claris Inferni, or Key to Hell, an 18th Century grimoire. You can see the other beautiful and compelling images from this manuscript at the link above.
L0036626 The Archangel Metraton, from Cyprianus, 18th C
Credit: Wellcome Library, London. Wellcome Images
Ink and watercolour image of the Archangel Metratron with seven lighted candles and seven gold stars, surrounded by alchemical/magical symbols in red ink. From Cyprianus, 18th century. Cyprianus is also known as the Black Book, and is the textbook of the Black School at Wittenburg, the book from which a witch or sorceror gets his spells. The Black School at Wittenburg was purportedly a place in Germany where one went to learn the black arts.
Pen and watercolour
Late 18th century By: M L CyprianusCyprianus, M. L.
Clavis Inferni sive magia alba et nigra approbata Metratona.
Copyrighted work available under Creative Commons Attribution only licence CC BY 4.0 http://creativecommons.org/licenses/by/4.0/