Changes

|Strength1 = [[Ultramarines]] [[Chapter]]<br>Ultramarine [[Successor Chapters]]<br>[[Imperial Guard]]<br>[[Grey Knights]]<br>[[Ultramar Auxilia]]<br>[[Ultramar Defense Fleet]]<br>[[Legio Fortis]]<br>[[Legio Atarus]]<br>[[Legio Oberon]]<br>[[Legio Praetor]]

The '''{{PAGENAME}}''' were a series of battles that occurred within the [[Realm of Ultramar]], between the forces of the [[Chaos God]] [[Nurgle]] and the [[Imperium]], after the [[Thirteenth Black Crusade]].

The seeds of the conflict were planted by Nurgle sometime before the latest Black Crusade began, when he decided he wanted to annex the prosperous worlds of Ultramar into his [[Garden of Nurgle|Garden]]. In order to do this he ordered commanded his forces to create [[Chaos Cults|Cults of Corruption]] and began spreading various diseases throughout three nearby Imperium Imperial [[system]]s, located to the galactic north of Ultramar. These systems are now known as the [[Scourge Stars]]. Controlled by the forces of Nurgle, they were used to launch fresh attacks against the Realm of Ultramar, in order to add its worlds to the Plague Father's Garden.{{Fn|1}}These diseases devastated many worlds, but it was only with the creation of the [[Great Rift]], during the Thirteenth Black Crusade, that Nurgle decided to fully act on his plans.{{Fn|1}}

Most prominent of these servants of Nurgle were the [[Death Guard]], which was launched a massive invasion of Ultramar led personally by [[Mortarion]] who gathered an enormous invasion fleet around him. In attacking Ultramar, Mortarion was not alone, however. Two ; two other commanders led massive armies out from the Scourge Stars, each seeking to win the contaminated glory of Nurgle’s Nurgle's favour.[[Typhus]], First Captain of the Death Guard, commanded the [[Plague Fleet]], a dilapidated rot-armada packed with Renegades, cultists and his own loyal Death Guard. A third major force, this time a host of Daemons, was led by the [[Great Unclean One]] [[Ku'gath]].{{Fn|2a}}. The Plaguefather and his demonic legions ravaged the [[Tartella System]], which lay between the Scourge Stars and Ultramar, before manifesting on the garden world of Iax, an ideal place to nurture new diseases{{Fn|3a}}.

The invasion force was too large for the defenders to engage directly but still too small to attack [[Macragge]] itself. Nonetheless, Mortarion launched many probing attacks on Macragge, often with [[Plague Drone]]s and [[Cultist]]s, in order to drain Ultramar's resources in Moraleand morale.{{Fn|3a}} Meanwhile, Mortarion moved on smaller more poorly defended worlds, slaughtering the populace in an attempt to goad Guilliman to battle. As worlds such as [[Iax]], [[Espandor]], and [[Ardium]] fell under siege , Mortarion had a secondary fleet under [[Typhus]] terrorize the outer regions of Ultramar, destroying three of the six major [[Star Fort]]s overseeing Ultramar's shipping lanes{{Fn|3a}}.

Guilliman, having just concluded the [[Indomitus Crusade]], eventually arrived with reinforcements to save the beleaguered Ultramar. First, he cleansed the Hive World of Ardium in the Maccrage System of its Death Guard occupiers. It was here that he learned Mortarion was using the ancient artefact known as the [[Hand of Darkness]] to craft [[Daemon Engine|Plague Engine]]s that were re-animating the dead and turning them into [[Plague Zombie]]s. Guilliman destroyed the Plague Engine on Ardium and freed the world from the influence of Nurgle.{{Fn|2b}}

Even with Guilliman's arrival, the attacks across Ultramar were still too many to contain. However , timely arrival of Ultramarines [[Successor Chapter]]s and reinforcements from [[Forge World]]s allowed Guilliman to take the initiative. On [[Espandor]], Guilliman launched the Spear of Espandor counterattack which that halted the Chaos advance and resulted in stalemate.{{Fn|3a}} The focus of this campaign was also to cut off the Death Guard off from the Scourge Stars which that were supplying Mortarion with an endless stream of reinforcements.{{Fn|2d}} The Ultramarines and their allies not only retook each of the lost worlds in the Espandor system but also destroyed the Plague Engines that were raising the endless tide of [[Plague Zombies]] on each of its worlds. After a ferocious battle in which the Ultramarines Chapter found itself fighting side-by-side with their Primaris Astartes brethren for the first time, the forces of Nurgle were routed from Espandor. Guilliman decisively ended the battle by slaying the Great Unclean One [[Qaramar]] with the [[Emperor's Sword (Weapon)|Emperor's Sword]] and destroying the last [[Daemon Engine|Plague Engine]] in the system. The Espandor System had been cleansed of the taint of the Plague God and the forces of Nurgle were now cut off from their base in the Scourge Stars. {{Fn|2e}} With Espandor contained, Guilliman launched a series of system-wide counterattacks.{{Fn|3a}}

With Mortarion's main attack on Espandor halted, the Daemon Primarch shifted his focus and joined with Ku'gath. Their supply lines to the Scourge Stars cut, their Plague Engines disappearing (which was slowly eliminating the constant tide of undead reinforcements), and more Imperial reinforcements incoming, the leaders of the invasion force would decide to throw the bulk of their forces against the world of [[Parmenio]]{{Fn|2c}}. On Parmenio, the largest armored and [[Titan]] battle of the war took place over the Plains of Hecatone. At the battles battle's height, Guilliman struck Ku'gath's vanguard and slew his Lieutenant , [[Septicus]]. In space, the Star Fort ''[[Galatan (Star Fort)|Galatan]]'' attempted to provide support, but was boarded by the [[Plague Fleet]] and massive casualties ensued, including the loss of the [[Novamarines]] [[Chapter Master]] [[Bardan Dovaro]]. Nonetheless, the Ultramarines and their allies made gains on Parmenio and Guilliman led a relief force to Iax.{{Fn|3a}}

The Ultramarines would then launch the [[Vengeance Campaigns]] where they led a coalition of their [[Successor Chapters]] and [[Knight House]]s across neighboring star systems of Ultramar, that had been overrun by the forces of Nurgle early on during the Plague Wars. This includes included the attempts by [[Marneus Calgar]] to liberate the worlds of the [[Tartella System]].{{Fn|4}}

**[[Legio Fortis]] - Demi-Legion

**{{Endn|2d}}: Chapter 20

*3: [[Warhammer 40,000 8th Edition Rulebook]]

*{{Endn|4}}: [[Codex: Space Marines (8th Edition)]], pg. 29