Editing Setting:Cloudburst/Glasians (section)

====Migration One====
The initial invasion caught the Imperium quite unprepared.  The Sector had a low number of psykers, whose dreams and forecasting might have granted more warning.  No active-duty military personnel in the Sector alive today remember the horrors of the first invasion, but the marks it left on Septiim and Maskos remain to this day.

When the Glasians arrived, they did so in far smaller force than they do in the present.  The invasion consisted of three large vessels, retroactively identified as the Glasians’ rough equivalent to the Apocaypse-class Battleships – very large, slow, and armed with the longest-ranged weapons possible.  Each was supported by a small flotilla of Escorts and a squadron of troopships.  The vessels simply appeared at the edges of the Drimmerzole, Maskos, and Septiim defense perimeters with no Warp signature, and promptly began shelling the living hell out of the startled Imperial defenders.

Even in the pre-Blue Daggers era of the Sector, however, its defenses and alliances of trust and mutual defense with other regions were not inconsiderable.  Five Astartes Chapters, Inquisitorial assets, and multiple Imperial Guard regiments mobilized to defend the region.  The Carcharadons were first to arrive, and took the fight to the Maskos fleet, while the Red Templars, the Angels of Fury, the Novamarines, and the Celestial Knights arrived piecemeal and in smaller numbers.  However, the unique nature of the Glasian technology proved a stumbling block for the Imperial retaliation force, which had distinct difficulty with the hovercraft and murderous plasma of the invaders.  Every Astartes Chapter that sent Marines took losses, with the Celestial Knights even losing a Strike Cruiser to the battleship over Septiim.

When the troopships arrived and began disgorging these strange vehicles and packs of howling-mad bird people on the planets below, the fighting grew even more disorganized.  The forces of Lord General Eustace Fowler took the invasion head-on, and eventually triumphed against the ground invasions, but an entire city on Drimmerzole Secundus was lost, with hundreds of thousands of civilians still in it, before the last of the aliens on the ground were slaughtered.

Finally, after grueling fights in orbit and on the ground, the aliens were defeated.  It did not take long for Librarians of the Angels of Fury to realize that the entire enemy force was contaminated from first to last with Warp energies and the powers of Chaos.