Yes...sorry i thought it was 3 haha! But niceI think you're refering to Chen Stormstout? If he was part of the founders of Orgrimmar, so was Rexxar, Drek'Thar and Gazlowe.
Ooo! ooo! I do number 2!
As far as my info would have carried me, the initial "Residents" of Azeroth were the Humans and the invaders were the orcs of the orcish clans of Draenor which was then recorded as the First War which crumbled the Human Kingdom which was Azeroth itself (The Human Kingdom of Azeroth) and forced them to flee back to Lordaeron.
Good answer but I think the question is bad. If you take the residents to be us, the Earthen, the Old Gods, the Titans or humans - you get all kinds of different answers!
You learn in Wrath, for example, that we invaded the Earthen and they consider us invaders as fleshlings
Who was the one called The Last Guardian?
What was the name of the world that Velen and the draenei came from?
What was the word that Velen used to call the other ones of his kin that chose the darker path?
Who is the one that holds doomhamer nowadays ?
Whos Llane, Lothar,Tyralion,Khadgar ?
What happened in Draenor... how did they turn from peacefull creatures to bloodthirsty and raging ones, who was responsable for this?
How exactly did the Ashbringer get corrupted? And how that guy from the Deathknight starter get his hands on it? (Not Tirion, the deathnight who tossed it to him)