These illustrations, mostly done in a style reminiscent of medieval Russian iconography, are from Russian editions of JRR Tolkien’s Lord of the Rings books.
They were painted primarily in gouache by Ukrainian artist Sergei Iukhimov. I haven’t been able to find much directly on Iukhimov, save multiple references to this particular series of illustrations.
The largest selection of images seems to be on the Russian site, Live Memory, with more on let us lie in the sun.
[Via io9]