Bane is a character from the Batman mythos.
He was born in a South American prison, due to his mother being imprisoned for a crime his father committed. He grew up under the eye of Bird, a criminal from Gotham City. Bane grew up to be the baddest, nastiest prisoner, and dreamed of going to Gotham. The Batman had come to represent all his fears and he believed that to defeat him would prove to all that Bane was the master.
The government was performing an experiment called Project Gilgamesh, which was to create an ultimate warrior. Aside from implanting plastic-polymer shielding into the subject to strengthen weak spots, like the temples, they also pumped him up using a steroid mixture called Venom. This stuff gave Bane incredible strength, but the kicker was that he could inject more of it right into his nervous system via a pipe from a box on his wrist to his head.
So Bane was the toughest guy in prison, and he had a burning crazy desire to kill the Batman. Some friends of Bird's broke them and two other prisoners out and they went to Gotham. There, Bane started by blowing a hole in the side of Arkham Asylum, letting out all the maniacs Batman had put away. Naturally, the Caped Crusader felt he should be responsible for catching them all, so he ran himself into the ground trying to catch them. In the meantime, Bane tracked him and watched him and worked out that Batman was in fact Bruce Wayne. Worn out from weeks of fighting loonies like The Joker, Batman didn't stand a chance, and Bane broke his back, leaving him paralysed.
Jean Paul Valley took over as Batman while Bruce Wayne was off finding a cure for his paralysis. He defeated Bane and then went absolutely gaga. Luckily, Bruce Wayne beat him, and took the job back.
Bane pops up every so often in the comic book. He was toned down seriously in the cartoon series, and was just a joke in Batman and Robin. I believe the best look at him is in the book Knightfall.
Bane is the only villain I can think of I truly despise. He is just a nasty, nasty man.
Among other things, Bane got himself off Venom, and popped up working for Lex Luthor (!) in the series No Man's Land - as Batman said to Bane in that book, "Without Venom, you're just another mook in a mask," and Bane ran away. Hahaha. The No Man's Land trade paperback also has a nice picture (which didn't happen) of Bane breaking the Joker's back over his knee, a pastiche of the Knightfall comic cover featuring the same scene with Batman. Bane did get to beat up the Joker, taking him by surprise as usual - the Joker wanted some attention from Batman and ended up with Bane: "I knew you'd come! Oh. This is gonna suck."
Though nice and all, the dramatic impact of the character is less when they bring him back every so often - it's like resurrecting Doomsday all the time in the Superman comics.