Warcraft is a real-time strategy game made by a little-known company called Blizzard Entertainment. That's right, it was basically Starcraft without the multiplayer. Or balance. Or ability to play as Orcs if I remember correctly. Hell, nobody played it as much as Warcraft II anyway.
From these noble beginnings, the Warcraft series would go on to spawn the second biggest license to print money in the history of the gaming industry, continuity be damned.