One of the main attractions of science fiction is world building–the creation of imaginary worlds adhering to a consistent set of "facts" about how that world works. While there are many science fiction books and series that demonstrate all that world building can do, few of them benefit from the creative input of multiple people over decades of construction. Warhammer 40,000 is one such universe. Let's take a bird's eye view of this spectacular world.
Warhammer 40,000 (also known as Warhammer 40K or simply WH40K) began as a game in 1987; specifically as a futuristic version of Warhammer, the fantasy-based tabletop miniature war game. The WH40K game featured science fictional counterparts to the fantasy creatures found in the Warhammer setting. Thus, orcs, a common creature in fantasy settings, became an alien race of Orks, and elves became the space-faring race of Eldar, and faraway lands were replaced with new, faraway planets.
Warhammer 40K has since evolved from tabletop gaming to encompass other forms of gaming (like board games, card games and video games) as well as other forms of media (such as prose novels, graphic novels, audiobooks, art books and film). The novels of WH40K (the focus of this nutshell look) include standalone novels, series, short stories and anthologies, and encompass one of the richest worlds science fiction has to offer.
The stories in the Warhammer 40K universe largely take place in the war-torn 41st millennium, hence the 40K in the moniker. Under the rule of the almighty and immortal Emperor, the Imperium of Mankind attempts to settle the galaxy while fending off the evil forces of Chaos, which includes enemies both alien and supernatural. The Emperor's forces include the Imperial Guard, the bio-engineered super-soldiers of the Space Marines, the members of the not-so-secret police known as the Inquisition, and the tech-priests of the Adeptus Mechanicus, among others.
The WH40K universe actually extends beyond the 41st millennium. Some precursor stories take place ten thousand years before the forty-first millennium. The popular Horus Heresy series of novels chronicles the events of the civil war that erupted when the Emperor attempted to reunite the scattered colony worlds of humanity under one government. The opposing forces were led by the warmaster Horus, one of the 20 genetically engineered Space Marine Primarchs created by the Emperor himself from his own DNA. The Horus Heresy marks the beginning of the Imperium of Man as it is known in the 41st Millennium.
Of interest to booklovers is the huge amount of written WH40K fiction set in this rich universe. Since the large majority of the books are about conflict, the tone of most Warhammer 40K stories is quite dark. Peace is just not in the cards in this universe. It makes sense; these are stories of a war-ravaged galaxy, after all. Or put another way: WH40K is more like the dark shadows of H.P. Lovecraft than it is the antiseptic spaceship hallways of Star Trek or even Star Wars. Yet on an individual story level, we see stories of heroism, determination, corruption, intrigue, betrayal and overcoming adversity from foes both human and monster. These stories encompass a broad range of events. They are complex and layered, vast and detailed, and completely engrossing.
You don't need to have played the Warhammer 40K game to enjoy the Warhammer 40K books. A fantastic introduction to the universe is the Eisenhorn trilogy by Dan Abnett. Eisenhorn is a member of the Emperor's secret police force, the Inquisition. Although many WH40K books focus on some of the military aspects of Emperor's efforts to squelch the forces of evil, the Eisenhorn trilogy reads like detective fiction, and a page-turning one at that. Abnett followed that up with another Inquisitor trilogy, Ravenor, and he's just started a new, related trilogy subtitled Ravenor vs. Eisenhorn that starts with the book Pariah.
If non-stop action is your thing, look to the novels of the Imperial Guard like Imperial Glory by Richard Williams or the Gaunt’s Ghosts series (beginning with Abnett's First and Only). Do you like galaxy-spanning drama? Check out the aforementioned Horus Heresy series (beginning with Abnett's Horus Rising). Some books feature events from the alien perspective, like Gav Thorpe’s Path of the Eldar trilogy (beginning with Path of the Warrior) or Eldar Prophecy by C.S. Goto. For a taste of horror, Ben Counter's Grey Knights series depicts the adventures of daemon hunters. Or perhaps you would enjoy the lighter side of this grim setting (if there can be one), in which case you might opt for the dark humor of Sandy Mitchell’s Ciaphas Cain novels, like The Emperor's Finest. Finally, if you are a book lover who is more visually oriented, you will also want to take a look at the art book The Emperor's Might edited by John Blanche.
Where you choose to start depends on your reading tastes, though it may be helpful to read sub-series in the order they were written since they maintain an internal chronology. Other than that, you can really dive in anywhere.
John DeNardo is the editor of SF Signal, a Hugo Award-winning group science-fiction and fantasy blog featuring news, reviews and interviews. He also likes bagels.