The Origins of the Storm of Reprisal
It is difficult to determine all the facets, twists and turns that would eventually culminate in the Storm of Chaos that sprung upon the world mere years after the rise of Heimgard, but exhaustive and intensive studies have revealed facts and manifested theories which, when pieced together, suggest a startlingly long and complicated series of events and planning which reek of the labyrinthine scheming mind of Tzeentch.
What is not quite implicitly clear but strongly suggested is that the beginnings of the Incursion were spawned in the end of the War for Norsca, when God-King Thorfin led the first Heimgardians to victory against the hordes of Chaos in a great clash that saw not only an Everchosen slain, but also the ascension of Thorfin to demigod status as an avatar of the Allfather.
One dare not even attempt to comprehend the impossible minds of the Four, but one can guess that the loss (never mind the eventual purification) of Norsca, the southernmost territory of Chaos worshippers, the source of their greatest and most far reaching raiders, home to a pantheon whose power they had all but subsumed...one can only imagine that it became rather close to "personal", one might say.
Though the Four clearly retained their contentious and fractious relationship, the greatest evidence of preparation for the Incursion years earlier than usual is the near immediate war that followed the rise of Heimgard. When the Lizardmen of Lustria were provoked into war against the High Elves of Ulthuan, it at first looked to be merely a Dark Elf scheme to set two of their greatest enemies against each other.
However, certain events that took place around that time and the recent Maternal Betrayal of Pleasure suggest even more sinister hands at work.
There is notable evidence that the war between Order's greatest and oldest defenders was orchestrated by Dark Elves under the sway of Morathi and through her the Dark God Slaanesh. Thus, the war was orchestrated with the intent of pitting the Lizardmen and Asur, Chaos' greatest and oldest enemies, against one another, leaving them weakened and perhaps even destroyed by the time of the Incursion. Later events suggest that even the discovery of the plot and peace between the two great powers was prepared for, which will be discussed soon.
Either way, thanks to thorough investigations on the parts of the Asur and Heimgardians, and mediation by the latter, the truth was uncovered and peace, though uneasy, reigned again between Lustria and Ulthuan, both declaring total war against the Druuchii of Naggaroth. Marienburg, Estalia, Bretonnia and the Empire quickly joined the conflict against the hated Dark Elves, along with punitive but effective raids by Heimgard.
Sheer numbers and initially grand enthusiasm led the allied fleets to victory against the Druuchi fleets that opposed them, until Malekith forwent futile attempts to seize victory at sea and dedicated his ships to raids and coastal support, as well as guarding the key passages into the Seas of Chill and Malice. The campaigns on land were somewhat more disjointed. Though the main allied forces centered their attacks around the High Elf colony of Arnheim, marching against various outposts and border fortresses of the Dark Elves, there was fragile coordination between the nations in these attacks, and significant disgruntlement.
Still, through sheer weight of numbers and the distraction afforded by the implacable Lizardmen advance from the south, a noticeable part of eastern and southern Naggaroth was cleared of Druuchii.
At the same time, forces from Estalia and Bretonnia were landed in the southernmost lands of Naggaroth, though not so far south they crossed into the isthmus connecting Naggaroth and Lustria. Though claims were made of spreading the attention of the Dark Elves from the allied concentrations further north, beyond efforts at clearing out Druuchi around the beachheads and headquarters, little attempt was made to carry the fight to Malekith's forces. These southern forces would later establish colonies, revealing the reason behind this lackluster southeastern campaign.
The rest, as one knows, is history. The Lizardmen armies, between the sheer martial prowess of their soldiers and magical might of the Slann, tore through Naggaroth, smashing aside what attempts were made to stop them and literally reshaping the landscape for greater ease of travel, until reaching Clar Karond and receiving Malekith's offering of all those involved in the murder of the Slann which precipitated the war. As Malekith himself was not targeted, and knowing of the proficiency of the Slann, who undoubtedly examined the offenders' minds, it is clear that the assassination came from a higher source alternative to Malekith.
After the Lustrians' abandonment of the war, a haphazard but devastating naval assault smashed through the defenders of the northern passages, breaking into the Seas of Chill and Chaos, and allowing an allied landing at Clar Karond, principle shipyards of the Dark Elves and one of the six great cities of the Druuchii. The dark place was looted and burned to the ground.
Thus were the Dark Elves struck an almost crippling blow.
At the same time, rumors reached Heimgard of Nippon's overseas expansion and subsequent troubles at holding onto such a colonial empire, and the rise of economic and military issues.
The rest is based largely on logical guesses using gathered, piecemeal information. Morathi, mother of Malekith and priestess of Slaanesh, under the cover of war with the forces of Order, made inroads among the peoples of Nippon, Cathay, and the Chaos worshiping tribes of Hungs and Kurgans to the west, well out of the way of the ongoing conflict. Ships were seized from the fledgling, disparate colonial empire of Nippon through deceit and subterfuge practiced for millenia and the mystic seductive arts of Slaanesh.
Thus was a force slowly formed in the wild east owing their allegiance to the Ruinous Powers in general and Slaanesh in particular. As Khorne's dominance waned following the myriad of defeats dealt to his forces, including several great heroes of the Blood God, Morathi's actions bore further fruit as Tzeentch, Nurgle, and Slaanesh preyed upon their weakened sibling and she was left unimpeded, veiled by the trouble afflicting Khorne which the other Gods of Chaos took perverse delight in and advantage of.
For all that the aspects of the Primordial Annihilator hate each other almost as much as everything else, there has always been a paradoxical long term willingness to support each other's plans even as, at the same time, they work to sabotage them. The mortal and sane mind might call it an unspoken agreement to work towards their greater interests even as they worked against each other's specific interests. Impossible one might say, yet so much involving the foul powers is.
Thus, while there is explicit evidence that Khorne's forces were savaged by opportunistic Tzeentchians and Slaaneshians as he sought to punish Heimgard for the humiliation it and it's revitalized gods had dealt him, one can infer that the lack of sabotage attempts against those plans and schemes that in general tended towards the benefit of Chaos as a whole were not so explicitly met with interference, such as Throgg's horde in the Troll Country and Morathi's great betrayal and overtaking of Nipponese and Cathayans ships alongside Hung and Kurgan troops.
The point is, that these greater schemes all spear to have been generally allowed to proceed for all intents and purposes since rise of Heimgard wth the mutual purpose of paving the way for a Storm of Chaos which might correct the balance, which had tilted more sharply than any other event since Magnus the Pious' reunification of the Empire. Perhaps even the rise of Sigmar and the Empire itself.
In these interim years between the War for Norsca and the great Storm of Chaos, Heimgard made substantial progress in its quest to root out corruption in its borders and develop new methods of dealing with the forces of Destruction. One of the "grand schemes" of a singular Chaos God that tended towards benefitting Chaos as a whole was swiftly and decisively beaten down in the form of the campaign against the troll Throgg and his hordes. Valkia, paramour of the Blood God, was slain by Ashi, wife of Thorfin and newly ascendant avatar of the Purifier. The Dharbreaks were created, granting protection against the foul forces in an unseen level.
The Skaven, ever given to treachery, had installed in their ranks puppet clans dancing to the tune of Thorfin's spymasters, that their foul desires might forever be impaired by their own willingness to back stab each other. A grand conference organized amongst the premier masters of the arcane that the nations of the Old World aligned to Order possessed, developing new and improved methods of purification and protection against Chaos. And Heimgard's star in general continued to rise, her culture improved, her defenses broadened, her ties strengthened. Ancient Albion, home to untapped secrets and humans largely dedicated to the fight against the Ruinous Powers, was slowly but surely brought into the fold of Order by Heimgard. The Norscan dwarves, longtime allies of Heimgard, were assisted in reuniting with their southern kin.
But all the while the tribes of the Chaos Wastes were gathered up, the fleets of the premier eastern states stolen, Morathi's power carefully and quietly built up, hidden under the cover of sheer distance and the pressing concerns of other demands and issues.
It is possible that the aforementioned force of pirated vessels and semi-willingly conscripted tribesmen was not so much a planned aspect of the Storm so much as a contingency plan. The fact that the year before the Storm came in earnest, Heimgard launched a raid against the forces gathering on the coasts of the Chaos Wastes which quickly developed into an established beachhead of undead, forcibly delaying Chaotic assaults on the Old World, as well as the massacre of thousands of Kurgans led by the Maw King, lends weight to that possibility. It suggests that Morathi's supply of troops was being impeded and forcing her to turn about, forcibly turning her attention from recruitment to preparing for war.
There is also the rise of Settra to consider, taking place that same year. No friend to the living nor the daemonic, his was something of a wildcard, and a powerful one.
Either way, the rest is as we know it. The initial assault on the Old World was partially checked by the great undead assault furtively supplied and aided by Thorfin and Heimgard along with the great Counter Storm, which set itself into the sky in all its beautiful, mesmerizing glory, pushing back the influence of Dhar and setting an aetherial shield over Heimgard, her greatest human ally Kislev, and even the northern sections of the Empire.
The attempted naval assault on the shores of the Old Word by Chaos worshipers deep in the Wastes was discovered early on by skeleton scouts, the water no hindrance to undead eyes. Though great sorceries and wretched rituals were enacted to hide the passage of the fleet of readers and marauders, the spellwork of the Loremasters of the Asur, with a general idea of where to look and what to expect, swiftly dispelled such attempts, unknowingly aided by the furthest eddies of the Counter Storm. From there, the allied fleets of the Old World forces of Order descended upon the Chaos fleet, which was great in number but of poor ship quality and ability in seamanship. Their best sailors and shipbuilders had left with Norsca. Their ships shattered, the barbarians slaughtered, their remains given to the sharks.
While in Naggaroth, a force which we have implicit evidence of being gathered years before the first indications of the Storm of Chaos was unleashed upon the wounded beast which was the Druuchii.
While there is no implicit evidence as to how many of the events that took place before the Storm of Chaos were preparation for it and not isolated events, there is no doubt that the Ruinous Powers had been preparing for and adjusting their general MO as a result of Heimgard's breakaway from the corruptive grip of the Primordial Annihilator.
2018 words
(Because there are some pretty strong hints, y'know?)