They saved the people of Stormwind, and not only did it cost them their lives, but then their bodies were taken by the invaders and desecrated into Undead, used as unliving weapons possessed by Orc necrolytes. In life, these heroes fought the Orcs to a standstill and even drove them back at times. In death, their debased frames were the first death knights created by Gul'dan the warlock.
They earned heaven and were instead given hell. They were the Brotherhood of the Horse, the finest knights and warriors the Kingdom of Stormwind had to offer. Their greatest leader and last member died on Blackrock Mountain, and since his death, no one has raised their banner. They gave everything to save their world and received only a mockery of death in return.
Before this fate, however, they served their kingdom as its most elite -- the best soldiers it had, the most feared military force humanity could then muster, and they proved it time and again. During the First War, the Orcs learned fear when they heard their horses approach and died battling against their lances and greatswords. It was this prowess that made them the targets of Gul'dan's ire.
We know very little of the individual members of the Brotherhood. Indeed, Anduin Lothar is the only one whose name has come down to us, as the 20th and final Armsman of the Brotherhood. What we know of them is as follows:
- They inhabited Karazhan at some point in time, either before or during Medivh's residence there. Many of the tower's internal architecture and motifs are inspired by the Brotherhood and bear its horse or horseman motifs. The presence of a stable in Karazhan is due to the Brotherhood's use of the place as a base.
- Garona Halforcen described them as "fiends rode atop beasts of muscle and sinew that crashed through our ranks" and credited them with the defeat of Blackhand the Destroyer's ranks during the opening of the First War. It was the Brotherhood who showed the Orcs that the farmers and peasants they'd slaughtered up to that point were not representative of all Humans.
- There were 19 Armsmen of the Brotherhood before Lothar. This puts the Brotherhood's founding at or just after the migration of Humans from Strom in the Arathi Highlands south to present-day Stormwind, roughly 1,000 years before the First War.
Once the First War begins, however, the Brotherhood's activities are far easier to trace. Effectively, every time the forces of Stormwind balked, stalled, or defeated the Horde it can be attributed to the Brotherhood. They drove the Horde back into the swamps from which it had invaded, keeping them penned up in what was then the Black Morass. When Lothar was captured trying to retrieve the Tome of Divinity, it was members of the Brotherhood who found and rescued their leader and proved their devotion to him.
When Medivh proved false and his betrayal of his world was revealed by his apprentice Khadgar and associate Garona, the Brotherhood were the ones who rode with Lothar to set things right. When Blackhand was deposed following Gul'dan's near death attempting to read Medivh's mind for the location of the Tomb of Sargeras, it was the Brotherhood who found themselves forced to deal with Orgrim Doomhammer and his revitalized Horde. And it was the Brotherhood who kept him out of Stormwind, despite his throwing every adult Orc he could find or drag through the Portal at them.
In the end, it was not Doomhammer's craft of war or force of his Horde's arms that defeated the Brotherhood of the Horse. No, it was the Shadow Council and plans that had been hatched before Doomhammer even assumed the mantle of Warchief. Gul'dan and his chief servant Cho'gall had planted a viper in the very heart of Stormwind. Garona was no mere Orc, but rather the product of Gul'dan's twisted breeding experiments, aged and controlled by magic. Worse, her already fragile sanity and sense of loyalties was destroyed by her association with Medivh and exposure to the twisted timeline of his tower, as she was forced to watch her own upcoming betrayal of Llane Wrynn. The Human king had treated Garona as no one else ever had, neither as an inferior nor a pawn, but as a friend and ally. The realization that murdering him was the reason the Shadow Council had let her leave their ranks broke her will, and she came to believe it was fated to happen.
The Brotherhood, already having lost many of their greatest knights in Stormwind's defense, was now presented with their darkest hour, and they rose to meet it as they had every other threat. Lothar needed a way to evacuate the city and the child king Varian Wrynn before the Orcs could catch them all. It was the Brotherhood who bought him that time, who rode out to meet the vast numbers of the Horde knowing they could never defeat such a press of numbers. Each of the Brotherhood who rode forth that day knew they were riding to their deaths, but they did so, screaming King Llane's name and defiance, and each of them sold their own lives for a great many orcs and bought Lothar the time he needed. And that could have been the end of it, but for Gul'dan.
The warlock, who had been the power behind Blackhand, awoke from his successful attempt to discover the location of the Tomb of Sargeras to discover that he was no longer in command. Doomhammer was not inclined to obey him (murdering the man's best friend might have had something to do with that), but following the nearly pyrrhic victory at Stormwind's gates, Doomhammer knew he couldn't keep the invasion alive without some means to overcome the Humans' superior technology, magic and mounted warriors. Gul'dan promised him a force that could ride and fight like the Brotherhood and use magic, and he used the Brotherhood and their loyal mounts to provide Doomhammer with said promised force.
Killing his own servants, Gul'dan used their souls to create jeweled truncheons, and placing those truncheons in the hands of the dead Brotherhood, defiled their corpses to rise as walking undead, their souls evicted and replaced by Orc warlocks such as Teron Gorefiend. Every death knight raised by Gul'dan, the ones who fought in the Second War and escaped back to Draenor to battle the Alliance Expedition, was a dead Orc's soul in a Brotherhood body. Thus Gul'dan had his revenge against the Humans who by killing Medivh nearly destroyed him.
Lothar's death atop Blackrock Mountain ended the Brotherhood. They exist today through their legacy, through Stormwind's survival, through those few death knights of the first generation who exist today (possibly including Karazhan's Attumen the Huntsman and the mysterious Dark Riders), and through the sword of their Armsman: Ashkandi, Greatsword of the Brotherhood. (Even that has been twisted, as it is doubtful the sword would have had a draconic motif.) It could be argued that groups such as the 7th Legion are their successors. But no one has ever truly replaced them. Perhaps it is time for Stormwind to call the Brotherhood back, but perhaps they've given enough and deserve to be allowed the rest Gul'dan denied them.
While you don't need to have played the previous Warcraft games to enjoy World of Warcraft, a little history goes a long way toward making the game a lot more fun. Dig into even more of the lore and history behind the World of Warcraft in WoW Insider's Guide to Warcraft Lore.