This is a very interesting Art Nouveau painting by the Austrian Maximilian Liebenwein (1869-1926).
Saint George, as though the world were full of devils... (1908)
Sure it’s not a real history painting, neither it’s a religious painting. It pretends to show Saint George but he’s painted as a medieval knight. As model for the costume and the title served the engraving from Albrecht Dürer (1470-1528) Knight Death and the Devil (1513).
The fantastic battle scene with the realistic costume reminds me also of the painting "Beserk" by the American fantasy artist Frank Frazetta (born 1928).
I don’t think that Frazetta knew Liebenwein or his painting. But it is a good example for the strong influence of history painting on modern fantasy art. When painters like Liebenwein abandoned the pretension to be "realistic" they turned into the forefathers of fantasy.