Originally Posted by Blizzard Entertainment

Just for some lore notes on the title itself...The title "High King" is more akin to the title "Supreme Commander" that was held by Anduin Lothar, being the commander of the Grand Alliance's armed forces. It doesn't serve to denote "rule", "legal authority", or any kind of faction-wide political control over the civilians of the races that make up the Alliance itself (outside of the case where Varian was the High King of the Alliance, and the King of Stormwind, making him the leader of the humans of Stormwind, obviously).We've discussed this a lot in the past, but the title and position of "High King" fits thematically with the Alliance - being an alliance formed originally around allegiances to human kingdoms.Much like the Warchief of the Horde serving a military role, the High King acts to try to coordinate the forces that he is given leave to command (races of the Alliance can refuse to commit forces to the High King). This does not necessarily mean that the entire group agrees with the High King at all times, but they do recognize and understand the need for organized military intervention.You may suggest that the humans should not have the title of High King, but as said above, there is a historical anchor within the Human Kingdoms for commanding the militaries of the Alliance, and they do believe they are better served by these Kingdoms than they would be by a Republic or Democracy.I don't personally think there is anything stopping the Alliance from choosing a member of another race as their commander, but it seems to me that, thematically, High King has been fitting of the title for some time. As said, the Alliance was founded as a collection of Human Kingdom, and there is historical weight there for the title of "King". Nothing stops titles from being changed, though.It is also important to note that the human's relative military strength compared to other members of the Alliance is much larger - especially that of Stormwind - which does give them some precedence in being appointed leader of the larger Alliance military.Let me see if I can get some answers on the "Why Anduin?" question. ( Official Forums