Marneus Calgar - Battle for Orar's Sepulchre: In 888.M41, an Eldar emissary from the Biel-Tan Craftworld was sent to the Imperial world of Commrath to enter negotiations with its Planetary Governor for the return of an ancient eldritch artefact from the tomb of one of the Ultramarines' most-lauded heroes, Captain Orar, known as the Sceptre of Galaxian. When the Imperial noble refused his request, the Eldar emissary grew angry and soon his pleas turned to threats of violence. The Planetary Governor refused to be cowed by the arrogant xenos and had the Eldar executed on the spot.However, the Governor had the foresight to heed the Eldar's threats and requested aid from the Ultramarines. Eldar from the Alaitoc and Iyanden Craftworlds then proceeded to assault the planet Commrath to recover the Eldar artefact within Orar's Sepulchre. Orar was a great Ultramarines hero in the aftermath of the Horus Heresy, and Chapter Master Marneus Calgar vowed not a single alien would breach the sanctity of his tomb. For the first time since the Battle of Macragge, Calgar lead his entire Chapter to war.The Eldar descended upon Orar's Sepulchre to find it held against them by the Ultramarines. Eldar Aspect Warriors and Guardians darted towards the main gates of the great edifice that was Orar's tomb as grav-tanks and artillery engines battered the Imperial defenders. On Calgar's command, the Ultramarines emerged from cover and scoured the invaders from the Sepulchre's steps with disciplined Bolter volleys. The Eldar fell back, only to find their lines of retreat cut off by Assault Marines and Land Speeders.Eldar leaders emerged from cover and rallied the trapped first wave, only to fall to sniper fire as the Ultramarines' Scouts made their presence known. The initial Eldar assault faltered but, for an entire day and night, they continued to attack. Though they mustered every arcane science at their command, they could not overcome the tactical brilliance of Marneus Calgar and his Ultramarines.The following day, a fresh assault swept onto the great stairs of the sepulchre, led by a colossal figure wreathed in flame -- an Avatar of Khaela Mensha Khaine, the Eldar god of war. Heavy weapons fire seemed only to anger the creature, and the Ultramarines' battle line buckled beneath its onslaught, so Calgar issued a challenge himself. The fiery god bellowed with fury, its first blow missing the Ultramarines' Chapter Master by a hair's breadth. The second tore plates from Calgar's armour. A third bit deep into his shoulder, driving the Chapter Master to one knee. But the fourth slammed into the armoured palm of Calgar's left hand.Rising up, Calgar struck with all his strength, bringing his other gauntlet around in a mighty arc that punched clean through the molten ichor of the Avatar's torso. With the fall of their war god, the Eldar lost all heart and retreated. Some fled without heed while others fell back in good order, but all of the xenos retreated into the darkness. Despite overwhelming odds, once again the Ultramarines had emerged victorious, but in his wisdom Calgar knew that the Eldar would return for the Sceptre of Galaxian. So it was that Calgar informed Commrath's Governor that the Galaxian Sceptre would be removed from Orar's Sepulchre to Macragge, where it could be properly defended.