An overview of the Ferdinand Cardinal Sector showing the Golden Trail of the Pilgrimage of Saint Ferdinand.
Out near the Eastern Fringe north of the spinward boundary to the Tau Enclaves in the Ultima Segmentum is the nebulae dense sector of Ferdinand Cardinal. It is recorded deep in the data stacks of the many Forge Worlds littered amongst the systems of this sector that the region was subjected to intense warp storm activity during M34-M36 which led to various portions of the region to experience the flow of time at different rates to one another. This would explain the many varied types of nebulae that are present within a relatively short stellar distance. Young proto-planetary nursery nebulae are scattered amongst regions of ancient planetary nebulae graveyards which sit side by side with diffuse nebulae of no discernible origin.
Indeed, no small number of these areas are thought to conceal warp realspace overlaps. Though only a handful of these have been confirmed and none of them are as large as Ultima Segmentum’s largest warp real space phenomenon, the Maelstrom, they are still large enough to justify a heavy Inquisition presence in the sector with many Inquisitorial watch fortresses and quarantined zones. The myriad nebulae in the system harbour dense planetary populations, with all manner of worlds within their gaseous boundaries. Occasionally new planets are birthed from these warp rifts and at times others will temporarily vanish or relocate within the sector. Since it's rediscovery this region of space has been contested by several factions and small areas of the Ferdinand Cardinal sector change hands on a regular basis, in fact it can be argued if the entire domain is really under any kind of Imperial dominion at all, though it is largely accepted that the Imperium does in fact control the region.
Another byproduct of this irregular flow of time was the rapid evolution of various xeno species that are found nowhere else in the galaxy. These species have no love for the Imperium and many have formed alliances to stave off eradication by man throughout the millennia.In fact, some races have lived and died out due to the time distortions, their entire existence played out in mere centuries of relative space time. It was during the formation of the strongest of these coalitions in the opening centuries of M37 that the Sector was rediscovered when the last remaining bastion of Imperial rule managed to contact an isolated Telepathica Choir station in the Vidar Sector, alerting the Imperium to the fate of one of their long lost outposts. This precipitated the start of the Holgstadt Relief Convoy, later to be recorded as the Ferdinand Crusade.
The Ferdinand Cardinal sector as a whole has been under Imperial control since its rediscovery in M37 by the Holy Crusade of Saint Ferdinand for whom the sector is named. The pilgrimage route follows the ingress by the relief convoy forces which became the Ferdinand Crusade upon the world of Regdan Exus where the blessed saint rose up and led the Imperium’s forces to smite the foul xeno armies of the Yarl’g. This was the beginning of the Imperium's percieved dominance within the sector. Even along the Pilgrimage Route, where the Imperium's presence is strongest there are areas that are outside the influence of Terra, xenos and mercenaries intermingle on alien outposts and space stations, their builders long gone and their technologies decaying and forgotten.
The pilgrimage route is populated with every conceivable type of Imperial world, all of which are guarded by fortress worlds on the peripheries of these productive systems. Beyond the pilgrimage trail the Emperor’s authority still extends but these are systems under constant threat from xeno, corsairs and worse. Constant vigilance is required to maintain Imperial rule beyond the periphery and there are several fleet based Astartes chapters on circuitous routes of the periphery lending aid as they see fit including two companies of the Emperor's Blades.
Many of the fortress worlds are at constant muster providing fresh regiments of Astra Militarum to feed into the many wars and skirmishes erupting beyond the watch of the Saint. A large Mechanicus quarantine zone is jealously guarded by the followers of the Omnissiah and no one is allowed in, the Mechanicum's activities inside are unknown and remain clandestine despite the Inquisition's continued investigations. There is also a plague zone which has been birthed in the last 50 years from Nurgle's garden of fecund entropy. This area is under the remit of the Emperor's Blades and they contain the plague and prevent it from spreading, though their proximity to the region also has also attracted the attention of one Inquisitor in particular.
Tertiary Nave of Adept Holgstadt in the Ferdinand Bascilica on the Diocese capital world of Surety
This is one of the reasons that there is an abundance of Mechanicus Forge Worlds dispersed amongst the systems of the Ferdinand Cardinal Sector. The scions of Mars were not idle during the isolation of M34-36 which is known as ‘The Detachment’. A great many worlds were colonised and the influence of the tech priests was extended far though this led to manifold schisms as the various worlds waxed and waned in power meaning that there is a corresponding number of independent fief enclaves as distinct from one another as any within the dominion of Mars. This was also the period in which they set up their quarantine zone. Picket fleets regularly patrol the borders of the zone and none have entered and left again to tell of what lies within.