One who is geekish about history. They (okay, we) have the same tendencies toward going on and on about their favorite subject as do other geeks, and the same belief that their particular field is really all that's important. They (okay...we) tend to ruin any sort of historically-set movie for anyone in earshot by constantly heckling the glaring errors.

Both more obsessive/obnoxious and more knowledgeable than a history buff, although not necessarily a history major. They come in many flavors and are fond of in-fighting even within time periods or regions, just as Red Hat users snipe at FreeBSD devotees. The only difference is, thanks to Hollywood and the popular press, history geeks get more chances to flaunt their geekiness in public.