Moab is an unremarkable world located to the galactic East of the great Forge World of Mezoa. Had it not been found at its location at a nexus of stable Warp-routes it is likely that Moab would never have been colonised. As it was, the world quickly became one of the most populous Civilised Worlds and even the administrative Sub-capital of the Cyclops Cluster. After several decades of prosperity which would eventually lead to its independence, Moab would suffer harshly during the Horus Heresy, becoming most famed for the dire events known as the "Sorrow of Moab." Reconquered in the aftermath of the galactic civil war, Moab quickly regained its former position within the Gothic Sector.
Whereas most worlds of the populous Cyclops Cluster had been colonised during the Dark Age of Technology, Moab's colonisation only began in the later Great Crusade-era when the Expeditionary Fleets of the Emperor's armies pushed into the northern reaches of the Ultima Segmentum. Although habitable, Moab is a chill yet desert world with high levels of local radiation, which seem to have deterred any further colonisation. Moab's value lies in its location, lying at the junction of several relatively stable Warp-routes that connected it to several important worlds of the Cyclops Cluster and the Manachean Commonwealth.
Moab's history began as a mere way station for the armies of the Great Crusade, quickly becoming a dormitory world first for the soldiers of the Exercitus Imperialis, then outward-going mining expeditions and labour armies. With the transition of several million people through its facilities, the original administrative and dormitory compounds expanded to become real cities served by their own water reclamation infrastucture and dust-agriculture fit to house the tens of millions of its native population. In 897.M30 this demographic evolution would eventually see Moab become a sovereign world with its own Imperial Commander. Moab continued to welcome colonists and imported workers, the influx of this human "livestock" -- often displaced involuntarily from recently Compliant or resistant worlds -- meaning that at the outbreak of the civil war, Moab's population would number well over one billion inhabitants. Moab's sole export, asset and stock-in-trade would be manpower, for it was a harsh realm where life expectancy was low and clean water a currency in and of itself. To ensure peace amongst these teeming millions, countless enforcers brutally ensured that the harsh laws of Moab's legal code would be respected. Politically and economically, Moab could not rival the influence of such worlds as Dominica Minor and Mezoa. This did not mean, however, that Moab had no influence at all; the planet boasted its own orbital gun stations and picket ships to ward off the almost inevitable Renegade and pirate attacks. Most important amongst these defences was Moab's primary orbital transfer and defence facility; a great geo-stationary space station fashioned from the hulls of past colony arks. To the Imperium, Moab's value was important enough to warrant permanent protection by several defence squadrons of the Armada Imperialis. These would be sorely needed on other fronts when Horus declared his secession from the Imperium, leaving the world utterly vulnerable to enemy intentions. As news of the Warmaster's revolt and the dire events of the Istvaan V Massacre become more widely known, an insurrectionist revolt flared up on Moab, the mob chanting Horus' name. With customary brutality, Moab's Imperial Commander, Malthus Grange, ordered the revolt to be put down, which led to a bloody five-week pacification pogrom by local enforcers and Adeptus Arbites. In the aftermath of this revolt, planetary martial law was declared.
The Sorrow of MoabEdit
At the same time the Death Guard Legion was leading the assault on the sub-sector-capital of Dominica Minor, Moab also came under attack; not by the pale-hulled warships of the Death Guard, but the deep viridian and sable vessels of the Sons of Horus. Using the neighboring gas giant for cover, eight Strike Cruisers of the Sons of Horus warfleet approached the planet -- at their apex was the Ikon, the dreaded vessel that had already delivered the Warmaster's ultimatum to other worlds such as Gethsamaine and Taracanis. This time the Ikon and her companion ships directly opened-up on Moab's primary orbital station with their Accelerator Cannons, easily overcoming the station's defences which was quickly boarded. The attack had been so sudden that Moab's ground defences barely had time to retaliate before the attacking vessels retreated again out of range of the planet's guns. Willing to spare his domain the devastation of a Legiones Astartes-led invasion, Malthus Grange quickly signaled his world's surrender, but the call went unheard and unacknowledged.
The signal was made again, this time on all available Vox channels, but still the fleet in orbit did not answer. Again and again the signal was made, with increasingly frantic and shameful pleas for mercy, while all the time the fear built on the planet and the tension mounted to a breaking point as the solar hours wore on. While the Night Lords were the Legion most renowned for their use of terror as a weapon, the Sons of Horus were well-versed in its application, too. Below, within their fortified enclaves, the muster-barons who ran the great labour barracks began to turn on each other, and civil insurrection and infighting broke out. The tension became unbearable until one or several muster-barons turned upon Malthus Grange. The next transmission of surrender now carried images of his bullet-ridden corpse as a further offering to the Traitor fleet. It was only then that the Ikon answered.
All across Moab pict-screens went live, showing the images of a savagely-armoured Astartes in a black plumed, snarling-masked helm, all but unrecognisable as omce one of the Emperor's finest warriors. They had made a beginning, the nameless captain of the Ikon told them, but it was not enough. Horus had sent him to save them from the Emperor's lies, and from the weakness he had fostered, and the due payment for this boon was to serve him. But only the strong, only those who deserved to survive would live, and the blood of the weak would buy them that survival. "Kill in His name and live, or perish with your Emperor's name on your lips. It is for you to decide." What followed was unspeakable.
Moab descended into anarchy. The streets ran with blood, cities were turned into open-topped slaughterhouses. A world murdered itself in fear of being destroyed by its new masters. Uncounted atrocities were committed in these days, and it was only several solar days later that the dark bulks of orbital lighters began to appear in Moab's skies and descended into its barrack-cities through the blood-reeking smoke that hung over them like a pall. Into their cavernous holds filed haggard, hollow-eyed men and women by the thousands, bound into Horus' service as foot-soldiers by a pact far darker than any sane mind could know or comprehend.
The Sorrow of Moab is one of the darkest chapters in the already sombre history of the Horus Heresy. Despite the breakdown of astropathic communication, news of the horror quickly spread. The sombre tale of Moab's fate would cause much civil unrest on countless Imperial planets. Even in the distant Agathean Domain, the dire events of the Sorrow would spark insurrectionnist and traitorous activity until the lauded former Imperial Commander Ireton MaSade rose to power and imposed planetary martial law.
Moab was the name of an ancient kingdom located on a mountainous strip of land in modern-day Jordan on the eastern shore of the Dead Sea. Thought to have emerged somewhere in the mid-ninth century B.C., the existence of the Kingdom of Moab is attested to by numerous archeological findings, most notably the Mesha Stele -- also called the "The Moabite Stone" -- which describes the Moabite victory over an unnamed son of King Omri of Israel. The Moabite capital was Dibon. According to the Bible, Moab was often in conflict with its Israelite neighbours to the west.
- The Horus Heresy - Book Four: Conquest by Alan Bligh, pp. 24, 34-35, 67