The History of the Protectorate-Tyranid Conflict - Background
By Historian Lagos Tyrll

The ongoing conflict with Tyranid forces established the Protectorate as a major power in the Sector. It also demonstrates the superiority of Liberation and Enlightenment over the dogmatic decay of the Imperium. The Protectorate's martial strength continues to grow, even as the rest of its institutions struggle to keep pace.

Thirty years after Liberation, the Diviner's Council observed that several Imperial worlds bordering the Sector had gone dark, their fates obscured by what we now recognize as the Shadow in the Warp, which blocked all scrying efforts.

In his wisdom, Liberator Cain dispatched an expeditionary force to investigate the threat. Force Kama Bravo—may their name ever be remembered—encountered Tendril Fleet Nautilon. The unknown Tendril quickly destroyed the fleet but the Ansiles provided crucial intelligence on the enemy's nature.

Thanks to the Handmaidens' infiltration efforts within the Imperium's leadership, the Liberation Council acquired critical intelligence about the Tyranid threat and a secret Imperium plan to abandon numerous planets and leave a trail of lifeless planets in favor of a fortified wall.

Unwilling to leave countless human lives to the monsters and recognizing the folly of allowing the threat to fester, the reconstituted Liberation Council acted decisively. They employed their unique skills and Warp connections in concert. In the spirit of Liberation and Truth, Ciaphas Cain declared the "Declaration of Tyranid Transparency." He publicly acknowledged the threat and vowed to break the Tyranids and ensure that the Flames of Liberty would never die.

The Disciples of the Great Architect established a monitoring network to predict Tyranid attack vectors and strengths. They engaged daemons from all three Recognized Powers to better prepare for the coming storm. Guided by Lord Ahriman himself, the Protectorate Psyker Corp (PPC) established the Diviner's Net, a great work of sorcery to monitor the entire Sector. This tool remains invaluable for identifying enemy movement, favorable warp currents, and potential threats.

The Unified Sector Army (USA) underwent significant reforms to address the Tyranid menace. These included integrating psychic and physical weaponry and developing specialized squads to neutralize Synaptic creatures. While not comparable in size to Imperial forces, the USA significantly expanded its capabilities. Mark II Liberators were widely deployed, while the advanced Mark III units served as rapid reaction forces and supported Astartes operations. Free Astartes were incorporated as commanders and strike teams, leveraging their unique skills. The Sons of Perturabo earned renown as the wall that repelled the Tyranids on countless battlefields. Meanwhile, the Thousand Sons—both flesh and steelbound—excelled in blending martial and psychic prowess to identify Synaptic creatures and deploy their forces precisely where needed.

As the Liberator famously stated, "Once Tyranids are on the ground, the price of blood will be heavy. We can make them bleed in the void without making them stronger." The Unified Protectorate Navy (UPN) was established as an independent entity to maintain supply lines and bleed the enemy in space. The Ambush of Circlius Maledictium exemplified the Protectorate's strategic approach. A cadre of Thousand Sons sorcerers, with the Fateweaver's blessing, enacted a ritual to attack Norn-Queens psychically. Unexpectedly forced into realspace, the tendril fleet suffered significant damage and was left vulnerable to combined UPN and allied daemonic forces. Although unable to be replicated, all Tyranid fleets slowed down, buying invaluable time.

Several Protectorate worlds were deemed indefensible by the Diviners. Rather than subjecting them to destruction or fighting doomed battles, the Protectorate leveraged their connection to the Powers and favorable Warp currents to exact a hefty toll. While much of the population evacuated, Sorcerors and Psykers enacted rituals to turn those planets into Daemon worlds, with the appropriate blessing and agreements, once the bulk of alien forces were committed. This tactic damaged the Hive Mind, leading several Tendrils to redirect from the Imperium to the Protectorate. Emeli's Garden(formerly: Keffia) continues to serve as a second headquarters of the Ascended Handmaidens, while Vashtorr's Forge(formely: Fecundia ) serves as a major manufacturing center for the BORG and naval hub.

The Handmaiden Intelligence networks backed by the contacts from the Van Yastobaal Merchant Empire were vital in preparing the battle space. Imperial worlds that were both potentially martially competent and willing to accept or at least tolerate the principles of Liberation were supported by Protectorate equipment and specialized trainers, the Red Berets. Subtle variations of the Imperial Truth laid the groundwork for future relations with the Protectorate. Unofficial agreements were established to prevent surprise attacks, while embedded assets were left to verify and warn if necessary.

Thanks to KingKeyna for permission to use some of his concepts and feedback.