Well, in Elder Scrolls IV: Oblivion. Necromancers were portrayed as the bad guys and you fight against them in the Mage's Guild quests. The necromancers in that game wore hooded black robes and created zombies.

Afraid I'm past that level of research by now. Last night I translated a French occult document to discover where the three supposed academies of necromancy (actually probably a bunch of cultists meeting in caves) were based. All in Spain, as it turns out.

Thanks for the thought though!

Nercromancry has a large hold in many cultures and has been used to spawn some of the coolest mosters in history. My peosonal favorite is either the hopping zombie fron chinese mytholgey, where corpses are controled with a scroll written in blood and placed on the fore head. Or the inugami, a loyal servent creatred from the soul of a starveing dog, however is know to somethimes posess their master if left alone too long. Then their is the nekomata, a cat monster who can reanimate and control recently deseced by hoping over them and then use their tails as puppet strings. I hope this helps you.

Not entirely certain what you are looking for here. Necromancy as it appears in gaming is often used as a form of magic, usually forbidden by society, that involves the raising of dead bodies for service or binding the spirits of the dead to things or living forever in some fashion.
Dungeons and Dragons places it as a category for types of spells that primarily involve creating undead or dealing with what they call "negative energy" which is the polar opposite of the spells that heal injuries or provide blessings and protections using "positive energy"
The Vampire game from White Wolf had the Giovanni family of vampires use Necromancy as one of their Disciplines (Branching it out further into more magical paths like Thaumaturgy in a later version of their system) Again the powers there dealt with making things appear dead, contact with ghosts, forcing ghosts to do stuff, binding them to objects, and making zombies.
Are you looking for famous necromancers in history? Or people to claim such?

Any background is useful. D&D supplements have been alright as far as outlining possible mechanics of necromancy, but what would be really useful are details of the rites practiced in the middle ages, some big names in the 'art', the titles of books that explore the subject, etc. Basically the same information I'd be after if I was doing a broad-spectrum research paper on the subject.

Luckily there were a fair number of relevant documents available online in pdf form, even if some of them are in French. 6,6

If my story is to be immersive, it needs to be grounded in things that actually happened. It can't be based on nothing but D&D rules and popular culture. Its roots need to be genuine. Unfortunately that may be impossible, for even some of the most valuable documents that survived the Dark Ages were written by clerics, based on information wrung out of captured and tortured necromancers. x,x

Literally, necromancy means "knowledge of the dead" - necro = "dead/death/the dead", mancy = "knowledge of." In its earliest forms, necromancers were people who petitioned spirits of the dead for knowledge; since the dead are beyond the mortal world - and beyond the constraints of time, depending on the setting/belief system - they are privy to secrets no mortal could conceivably know. Therefore, any mortal capable of finding a spirit with the appropriate knowledge and the ability to appease/bind it could learn the spirit's secrets. This is a great power since the secrets of the dead are tremendously powerful in the mortal world, either in the form of magic powers or insight into a particular situation (if not the world in general). Merlin, of Arthurian legend, was a necromancer; and many of the Greco-Roman myths about people descending into the underworld, or approaching its edge, to converse with spirits is a form of this kind of necromancy.

As with most pagan beliefs, this sort of necromancy fell out of favor with Christian teachings as Christianity spread and became lumped in with occult studies and devil worship (in Western culture, at least). This, coupled with Gothic horror fiction and the like, gave rise to the necromancy we see in modern gaming systems: a form of magic, usually associated with evil and vindictiveness, wherein corpse or spiritual entities are bound to the spellcaster's will. Whenever a game system incorporates magically-empowered undead, this is usually the domain of necromancy. The most general case of this would be Dungeons and Dragons, though as of 3rd edition it listed necromancy as a school of magic with power over life and death, i.e. not a necessarily evil brand of magic, though some spells are decidedly not the sort decent adventurers or magic-users would cast (like trap the soul). Granted, in 3.5 edition, Dungeons and Dragons moved healing magic from the domain of necromancy into the school of conjuration (summoning powers) and left most of the magic dealing with undead, fear, and death-powers in the school of necromancy. As such, necromancy's interpretation is highly subjective to the media in which it appears, and game balance plays a particularly important role in how it will fit.

Another game example - Werewolf: The Forsaken ties werewolves closely with spirits and spiritual creatures. Since appeasement of the spirits in W:TF can grant individual werewolves or werewolf packs special knowledge or power, this fits in with the original context of necromancy. Still, the interpretation of spirits in the rebooted Werewolf seems more like a cross between Shinto spirit worship and a generalized interpretation of American Indian spirit worship, so it's more like shamanism than necromancy in its popular form.

Necromancy also appears in literature as well, though not always codified as necromancy. The works of Howard P. Lovecraft, particularly those dealing with underworld beings and the strange powers associated with them, sometimes touch on the ritual animation of corpses, knowledge gleaned from spirits and the like. The story "The Festival," references indirectly how a dead wizard's spirit (a terrible thing, in Lovecraftian lore, since the powers beyond mortal ken are terrible and brain-twisting to behold, let alone wield) might inhabit the worms that feed on its buried corpse and force them to act as its body so that it might continue to function in the living world. In the story "Imprisoned with the Pharohs," Lovecraft ghostwrote a story about the dark secrets of ancient Egypt, the Sphinx and the ritually buried dead (notably composite mummies of animal and human, partially ruined mummies, spirits whose mummies were destroyed or mummies whose spirits left for the worlds beyond, etc), while "The Horror at Red Hook" mentions the reanimation of a newly dead man (whom retains his will once revived) by a creature hinted at being Lilith. Blending science with the occult, there is "Herbert West: Reanimator," wherein a medical grad student makes it a life quest to make a formula that will revive a dead body to life again while his partner (the narrator) speculates on what a mind awoken from the dead would have to say or how it might act. The stuff Lovecraft wrote about might not be necromancy as a specific form of power, but it has much of the trappings, including the traditional horrifying aspects of it. When the Cthulhu mythos is put into game terms, however, the undead that appear would not be unfamiliar to most fantasy gamers, but they're played up much more for their horrifying, unearthly aspects and the shock their existence causes to mortal minds.

I'm not as familiar with Asian necromantic traditions as I am Western ones, but as Inktail mentioned, there are a host of fascinating undead beings (or what we would classify as undead) spawned from the various folktales and religious traditions. From what I have observed as a whole, the necromancy of Asian tradition ties in with spirit worship and the idea that all things have spirits, and that spirits have a single, driving ideal that might keep them going well after their physical anchors have gone away. The hopping vampire, for instance, is supposedly a creature made when a man dies and the good portion of his soul passes on but the wicked part remains in his body; since the body does not have a complete soul, and because it is decreased and in partial rigor, it is very stiff and moves by hopping around - though it is every bit as powerful as the vampires we know from Western tales. I think there's also another kind of creature, which might be undead or a form of evil spirit/monster that's basically a flying vampiric head trailing a cluster of organs from its throat that kills people in their sleep, removes their heads, and nestles on their necks to use their corpses as its own body since it would die at sunup without that sort of anchor.

In an extremely broad sense, any form of ritual - be it arcane or scientific - that deals in communicating with or reanimating the dead could be considered a form of necromancy. Granted, that is a bit of a stretch (especially where the lately popular viral zombies, such as from the Resident Evil games, the Left For Dead games or in the book World War Z) since the "undead" in them are really just corpses reanimated into human-shape animals, but that depends on how closely you want to tie whatever scientific reasons those settings create for the undead with the alchemical traditions of old.

You might want to look at this book - http://www.amazon.com/Element-Encyclopedia-5000-Spells-Reference/dp/0007164653/ref=sr_1_1?ie=UTF8&s=books&qid=1265221722&sr=1-1

China Mieville "The Scar" had a city of the undead in it. The zombies formed the countless bulk of the population, with a living stock of humans for new recruits and for fine details that dead fingers have a hard time working out. Pickled/stitchwork mummies for liches are the rulers of the bunch, while vampires/"ab-dead" are consider beggers to be pitied for their chemical dependency on living blood.

As for necromancy, the Dresden files did a bit about how the necromancer needs to simulate a heartbeat through drums or music, to fool the body that its still alive and that the spell caster is now the brain of the outfit.