Horus - Triumph of Ullanor: Though the Luna Wolves had won many victories in their years of ceaseless conflict, one would eclipse all others and see them reborn once again. The greatest of the nascent Imperium's victories during the high point of the Great Crusade came in the form of the defeat of the largest Ork empire ever encountered.The Ullanor Crusade was a vast Imperial assault on the Ork empire of the Overlord Urrlak Urruk. The capital world of this Greenskin stellar empire, and the site of the final assault by the Space Marine Legions, lay in the central Ullanor System of the galaxy's Ullanor Sector. The Crusade included the deployment of 100,000 Space Marines, 8,000,000 Imperial Army troops, and thousands of Imperial starships and their support personnel. The Ullanor Crusade marked the high point of the Great Crusade's vast effort to reunite the scattered colony worlds of humanity.The Orks of Ullanor represented the largest concentration of Greenskins ever defeated by the military forces of the Imperium of Man before the Third War for Armageddon began during the late 41st Millennium. Following the defeat of the Orks of Ullanor, the Emperor of Mankind returned to Terra to begin work on His vast project to open up the Eldar Webway for Mankind's use. In His place to command the vast forces of the Great Crusade He left Horus. In the aftermath of this Ullanor Crusade, Horus was granted the newly-created title of "Warmaster," the commander-in-chief of all the Emperor’s armies who possessed command authority over all of the other Primarchs and every Expeditionary Fleet of the Great Crusade. Before returning to Terra to oversee the next phase of the creation of His stellar empire, the Emperor suggested to Horus that he rename the XVIth Legion the "Sons of Horus," in honour of their Primarch and to show his preeminent place amongst the other Primarchs.Horus initially declined this honour, not wishing to be set above his brothers, and so his Legion continued as the Luna Wolves for a little while longer. But Horus and the other Primarchs never came to terms with the Emperor's absence. Their hurt feelings over His seeming abandonment of the Great Crusade to pursue a secret project whose purpose He chose not to reveal to His sons laid the seeds of jealousy and resentment that would ultimately blossom into the corruption that begat the Horus Heresy.Following his promotion to Warmaster, Horus had solicited the opinions and advice of all his brother Primarchs on the subject since the honour had been bestowed upon him. Being named Warmaster set him abruptly apart from them, and raised him up above his brothers, and there had been some stifled objections and discontent, especially from those Primarchs who felt the title should have been theirs.The Primarchs were as prone to sibling rivalry and petty competition as any group of brothers. Guided by the shrewd political hand of his Equerry Maloghurst, Horus had courted his brothers, stilling fears, calming doubts, reaffirming pacts and generally securing their cooperation. He wanted none to feel slighted, or overlooked. He wanted none to think they were no longer listened to. Some, like Sanguinius, Lorgar and Fulgrim, had acclaimed Horus's election from the outset. Others, like Angron and Perturabo, had raged biliously at the new order, and it had taken masterful diplomacy on the Warmaster's part to placate their choler and jealousy. A few, like Leman Russ and Lion El'Jonson, had been cynically resolved, unsurprised by the turn of events.But others, like Roboute Guilliman, Jaghatai Khan and Rogal Dorn had simply taken it in their stride, accepting the Emperor's decree as the right and obvious choice. Horus had ever been the brightest, the first and the favourite. They did not doubt his fitness for the role, for none of the Primarchs had ever matched Horus’ achievements, nor the intimacy of his bond with the Emperor.It was to these solid, resolved brothers that Horus turned in particular for counsel. Dorn and Guilliman both embodied the staunchest and most dedicated Imperial qualities, commanding their Legions' expeditions with peerless devotion and military genius. Horus desired their approval as a young man might seek the quiescence of older, more accomplished brothers.