Second only to Abhorash in fame is the great Walach Harkon. It was he who created the greatest order of Blood Knights, the Blood Dragons.
History
Harkon does not share his master’s piety - he does not, for example, feed only on criminals - but he does share his devotion to perfection and believes the vows of knighthood are the best way to achieve it. Many believe Harkon takes this too far, as he insists on mimicking every aspect of knightly ceremony, including, since the death of his great love Aurora, absolute chastity. Harkon hears no argument, however, and considers anyone who does not follow his traditions to the letter to be undisciplined swine, better culled with the humans than allowed to further insult the purity of the order.
Storm of Chaos
Harkon was also greatly insulted by the mortals who removed him from his glorious Blood Keep. His goal, now that he has returned, is to make both the upstart mortals and his fellow Vampires recognise once again the singular superiority of Blood Keep and its knights. Walach has sent word to all the Blood Dragons that those who consider themselves worthy should join him in rebuilding the keep and in his new vision for the order. This is not just to reinstate the keep but to use it as the centre for his campaign for total extermination of the human race. With the main body of Empire troops still in the west after the Storm of Chaos, there would be little to stop an army of Vampires from the east, and if Harkon gathers his strength quickly, he could very easily make his dream a reality.[1]
End Times
During the End Times, the newly resurrected Nagash started recruiting many of the world's most powerful undead lords to form his generals. Harkon joined and became one of the Mortarchs. To this end he played a vital role in the defense of the Auric Bastion in the northern Empire. Under the command of Vlad von Carstein, Harkon fought at the Battle of Alderfen. Here a Nurgle force breached the bastion and started butchering the Imperial forces beyond it. All looked lost until the surprise undead counter charge, led by Harkon and his knights, halted the Chaos advance long enough for the breach to be sealed. However, in his zeal Harkon and his knights had penetrated far beyond the Bastion itself and then found themselves trapped behind it.[2]
It wasn't until the Battle of Heffengen that Harkon would resurface. After the collapse of the Bastion, Von Carstein sought an alliance with the Empire and to this end planned to fight alongside the Imperial forces at Heffengen to hold back the Chaos hordes led by Crom the Conqueror. Just as he was about to reveal himself and be recognized by the Emperor as a hero and ally Harkon and he knights charged onto the battlefield from the Chaos lines. It was revealed that while trapped behind the Bastion, Harkon had fallen to temptation and pledged himself to Khorne the Blood God of slaughter. This treachery reached it's peak when Harkon, riding a skeletal dragon, engaged in an aerial duel with Karl Franz, defeating him and casting him low.[2]
With the apparent death of the Emperor the Imperial forces retreated and the battle was lost. However, with the armies of the Empire now unwilling to accept the undead as allies, von Carstein would not let this action go unpunished. When Harkon swept from the sky and pinned von Carstein to the ground, Vlad used his superior magical abilities to wrest control of the skeletal dragon from Harkon and had the beast rip it's former master in two, destroying the traitorous Blood Dragon.[2]