Released by blizzard in 29th of June 2000. Created by the famous Blizzard North Group.
The story of Diablo II takes place after the end of the previous game, Diablo, in the lands of Sanctuary where Diablo, the Lord of Terror, was defeated by an unnamed warrior. The hero who slew Diablo drove the demon's soulstone into his forehead in an attempt to contain him, but this is what Diablo wanted and just made him stronger, and the adventurer is in turn corrupted. The player is an adventurer who appears in the wake of the destruction caused by Diablo and attempts to find out the cause of the destruction, starting with the corrupted warrior (from the first game). As the player continues through each of the four acts, he faces off against the Prime Evils, superpowers of Hell, and the two lesser evils who once overthrew the three prime evils, and learns of the truth behind the corruption. Diablo released Mephisto (Lord of Hatred) and Baal (Lord of Destruction) from their soulstones, as they were taught long ago how to corrupt them by the fallen angel Izual. In the end, the player eventually reaches and slays Mephisto and Diablo. The story continues in the expansion to the game, where the player chases the last of the Prime Evils; Baal (Lord of Destruction) who is going after the mythical Worldstone in an attempt to corrupt it. http://en.wikipedia.org/wiki/Diablo_II