The tauren have often been viewed as the "good" guys of the Horde. While the orcs, blood elves, forsaken and trolls have all had various unsavory qualities, the tauren race stands out as a genuinely peaceful, altruistic race of spiritual people that want nothing but what's best for the earth and the spirits it contains. Despite their seemingly good intentions, this does not leave the tauren without conflicts of their own, and when a closer look is taken at their current activities, some questions still beg to be answered. The history of the tauren is arguably just as lengthy as that of the orcs or the blood elves, the major difference being that the history of the tauren race isn't really documented anywhere to be seen save for a small set of scrolls on Elder Rise in Thunder Bluff. Given that the Horde in general seems to lean more towards using violence to solve their conflicts, where do the tauren fit in, and why did they choose to sign up with the Horde in the first place?
The answer stretches all the way back to Warcraft III, when Warchief Thrall traveled to Kalimdor on the advice of the Prophet, a mysterious figure who would later be revealed as Medivh. After landing in Kalimdor, Thrall and his people found themselves in a much harsher land than the one they'd left, with new enemies like the centaur, a tribal race of primitive, bloodthirsty creatures, half-humanoid and half-horse in appearance. But Durotar was not without allies, as Thrall discovered when he happened across the tauren.
The tauren were originally nomads with no real "home" to speak of -- they simply traveled from place to place, living off the land in large groups or tribes. It is unknown as to how many of these different tribes actually exist, because of this nomadic nature. As they never really settled in any one particular place, the tauren were literally scattered all over the world, though the majority of them were concentrated in Kalimdor. Thrall came across a tauren who was under attack by the centaur and saved him, a tauren from the Bloodhoof tribe led by Chieftain Cairne Bloodhoof. Chieftain Cairne was both grateful for the rescue of his tribesman and intrigued by the nobility and savagery of the orcish race. He explained to the warchief why the Bloodhoof were traveling; while his people had been nomads for centuries, Chieftain Cairne wished to return to the verdant lands of Mulgore, the ancestral homeland of his people. Thrall spoke of the orcs and their flight to Kalimdor to find their destiny, and Cairne told him of an oracle to the north, offering to give him the location of the oracle in exchange for protection from the savage centaur on their journey to Mulgore. Thrall agreed, doubtless feeling no small connection to the chieftain and his wish to find a stable place in which his people could settle and thrive.
While this was all well and good, the pledge he'd sworn to Thrall had been fully repaid and the tauren were no longer indebted to the Horde. This changed when centaurs captured Cairne's son Baine. Cairne fell into a deep depression; his son was everything to him, and without him he saw little hope for his people (sort of like King Varian Wrynn and the all-encompassing depression he fell into when his wife Tiffin was killed). Cairne's second-in-command, a tauren named Tagar, tried his best along with the other tauren of the tribe to keep the tribe running smoothly, but without Cairne's leadership, it looked as though the tauren would soon die out.
Enter Rexxar, a half-ogre, half-orc of the Mok'Nathal clan. Rexxar, along with a troll shadow hunter named Rokhan, had been sent to ask for the aid of the tauren against the Alliance -- not the Alliance we know today, but the Kul Tiras, led by Admiral Proudmoore. Jaina's father did not share her ideals for peace and a treaty between Alliance and Horde. He merely wished the lot of them eradicated as quickly as possible and started by attacking the outlying orc settlements in Durotar. Upon arriving in Mulgore, Rexxar and Rokhan asked the aged tauren chieftain for aid. Chieftain Bloodhoof, overcome by grief over the loss of his son, told the two to go back to Thrall and tell him that Cairne Bloodhoof was dead. Rather than taking this tactic, the two chose instead to go retrieve Baine from the centaur and bring him back to his ailing father in one piece. Grateful beyond words, Cairne once more pledged his people's assistance to the Horde. After wiping out the Kul Tiras forces, Cairne and his people again returned to Mulgore and built Thunder Bluff as a refuge for their people where tauren of every tribe were welcome. Over time, the scattered tauren tribes gradually united under Cairne's rule, and this is how the tauren that we see in World of Warcraft were established.
Despite his age, Cairne is still believed to be the wisest and best suited to lead, regardless of his personal feelings on the matter. Along with Cairne, the Archdruid Hamuul Runetotem and the elder crone Magatha Grimtotem help lead the people, though in more of an advisory aspect than an active one. While the archdruid was a natural choice, it was the choice of Magatha that caused a few players to wonder, as they were leveling their characters through the original game, why the elder crone was allowed in Thunder Bluff at all, much less to help lead the united tribes. It made little sense, and as story lines and quests progressed, it became ever clearer that Magatha and her people weren't the same kind of tauren players were used to seeing.
The Grimtotem tribe is one of the mightiest of the tauren race, but also one of the most aggressive. While most tauren tribes seek nothing more than peaceful coexistence with the world and the spirits, the Grimtotem fight to eliminate enemies of the tauren. Unfortunately, to the Grimtotem, all races are enemies of the tauren people, "lesser races" that should be eradicated. Sounds a little familiar, doesn't it? Magatha and her tribe felt that the alliance with the Horde was a bad idea, that Kalimdor belonged to the tauren and no other race should hold claim to it, any of it. While the two main settlements of the Grimtotem are located in Stonetalon Peaks and Thousand Needles, other Grimtotem settlements can be found in Feralas to the south and Dustwallow Marsh to the east. Magatha, however, lives on Elder Rise in Thunder Bluff and helps Cairne lead the combined tribes of the tauren race. Magatha's ideals are ... different, to say the very least. She became the matriarch of the Grimtotem clan through an arranged marriage, and after her husband's death in an unfortunate "climbing accident," now leads the Grimtotem clan on her own.
Despite the shady dealings between the Grimtotem and the forsaken, and despite the outright hostility that the Grimtotem hold towards all other creatures, Chieftain Cairne still allows Magatha into Thunder Bluff to help him. Why would Chieftain Bloodhoof, a strong proponent for peace and understanding, allow a tribe seemingly driven by hatred into Thunder Bluff? Why would he take her advice? Why would he keep her nearby, and most importantly, why is she not being held accountable for the actions of her people? The only answer that can be divined from everything known about the tauren and Cairne is this: Cairne is indeed a strong proponent for peace and believes that all tauren, no matter what tribe they belong to, should be united. Perhaps he also believes that the Grimtotem are simply misguided, and giving them an example to follow will eventually lead them down a more peaceful path. Perhaps he simply wants to keep Magatha close at hand, to keep an eye on her and make sure that whatever her people are doing, it is not without careful observation -- to let Magatha and the Grimtotem know that they are being watched. But what is the point of letting a tribe know they are being watched, if nothing is being done when they cross a line that should not be crossed?