The Divine Purging

The Diving Purging is the name of the event that involved the White Scars Chapter and elements of the Ordo Hereticus to purge the secessionist elements within the Utrar Khanates - a cluster of half a dozen systems in the Segmentum Ultima settled during the Great Crusade. Following the successful purgation of these rebellious elements and bringing back the Emperor's justice to this region, it was decided that a new Space Marine Chapter should be created in order to stand eternal vigil in this highly volatile region of the Galaxy. This conflict directly led to the creation of the Storm Sons, a Successor Chapter created from several veterans of the White Scars Chapter that took part in this Imperial campaign. Since that bygone era, the Storm Sons have continued to stand vigil over the Utrar Khanates.

Background
Despite a prosperous beginning rooted in the dawn of human unity, the demands of the Great Crusade and the events of the Heresy eroded at the Terran authority installed by the V Legion. Imperial Governors through generations of nepotism and mismanagement were recast into self-styled emperors and dynasties, resulting in eight millennia of poor administration, petty squabbling and the inexorable technological and cultural decline that followed.

As the Khanates slowly fragmented into thousands of petty kingdoms, empires and vassal states competing for dominance, the lack of Imperial guidance eventually took a much darker turn: one by one, the outer systems slipped from the Imperial fold entirely when the Empress of the Qhwarazheen Dynasty, the largest Khanate empire of its time, fell sway to the Eternal Foe towards the end of M38 and overthrew the last of the pro-Imperial confederacies.

The Imperial response was absolute: a purge action led by the Ordo Hereticus with three regiments of out-system Astra Militarum, supported by an Ecclesiarchy militia. In the third year of hostilities as the conflict spread throughout the sector, an instrumental ally came from an unexpected quarter: an Adeptus Astartes strike force comprising of the White Scars and their successor chapter Storm Lords, a total of 48 Space Marines.

Within days, the combined White Scars force led the assault on the Qhwarazheen palace compound. Once the Empress had been deposed, no less than two planets within the sector were sanctioned extremis to contain the influence of the Chaos. The Qhwarazheen Dynasty and their vassal states were eventually annihilated, a moon utterly destroyed, and more than a third of the entire sector's sixty billion strong population perished in the conflict or executed thereafter by Imperial forces during the subsequent purging.

[NB: For a full account of the Qhwarazheen Dynasty's crimes against the Imperium and subsequent military action, reference file ++CF-W12332-5433++]

Noting the Astartes merciless punishment of their distant gene-cousins, the Inquisition's support for the formation of an Astartes presence to guard and enforce Imperial interests in the region was expediently ratified by the High Lords of Terra. Stable gene-seed derived from the Storm Lords was entrusted to Storm Lords commander Torgha Khan and formalised as a Chapter, drawn from the remnants of the combined Astartes strike force.

For two thousand years since its formation in a period named by Imperial scholars as Pax Chogoria, the Storm Sons have guarded the Utrar Khanates against corruption, re-moulding its culture into a model Imperial vassal sub sector, lest the populace faces the wrath of the Khagan once again. Under their jurisdiction, the Khanates have been moulded into a diverse and potent recruitment pool for the Astra Militarum, and to date have raised several decorated regiments such as the XXIInd Utrar Mhukals and the vaunted outriders of the Ordu Zolhotaya.