Inquis Exterminatus is an art book compiled by John Blanche for The Black Library, and first published in 2000 (my edition is from 2011) and which, at the time of writing this blog post, is sadly out of print. It contains around 140 pages full of artwork from all way back to Rogue Trader until late nineties, and from many artists, not only John. Also there are some companion texts and "motivational sentences", always related with the pictures they appear along to.
The contents are separated by armies/factions, containing one for imperials and heretics, another for chaos space marines/traitor legions, and then xenos races. The last pages contain some beautiful sketches that I wish there were more of them.
It is a nice art book, and one I'll keep, but my only and big complain is that some of the pictures are in black & white despite the original being in color. They are still great but having seen the coloured ones it is a pity that the book contains the B&W alternative. There are some color drawings so I don't get the reason why all that should aren't coloured. But even with that is a great compilation.