Mount and Blade is a 3D, open-ended, single-player, third- or first-person, computer role-playing game, created and distributed by the Turkish development house TaleWorlds. Mount and Blade has a medieval setting, without any fantasy elements. Mount and Blade is notable for its emphasis on realistic cavalry combat, which was common in the era, but is largely absent in most RPG titles.
Played the singleplayer for almost 3 years, and the Warband multipayer for half a year now. Game is great, and has the best melee combat system if any game I've ever played.
There is however no reason to buy the first Mount & Blade, unless you just want to support the devs or if you're a collector. Mount & Blade: Warband has everything the first had and more, most importantly multiplayer.