So how did the world of Azeroth come about? The very first in the series of successful Warcraft game leading up to WOW is simply called Warcraft: Orcs and Humans or Warcraft 1. Anyways this game was released in 1994 by Blizzard.
 

This is one of the very first RTS games I remember playing. In this game you either played the Humans or those nasty little Orcs. Basically you had to manage resources and troops and go explore to find more resources and engage the enemy. This game was only supported 2 players or a campaign mode. Buy over all this game set Blizzard apart from the other in quality of its games and content  in its games.

Over all this game was entertaining to play but had it quarks, like not being able to control more than 4 units at a time, but for the most part this game rocked... If you never played this game its on the AbandonWare list so it is available free for download.

If you never played this First of the Warcraft series it's definitely worth checking out to see where it all started.