Golden Throne - War Within the Webway: As the Horus Heresy erupted, after many long solar months with no contact with the Emperor, Malcador and the Imperial Fists Legion's Primarch Rogal Dorn were finally granted an audience with the Master of Mankind. The order to appear before the Emperor had been timely, coming as it did just as news had reached Terra of the disaster of the Drop Site Massacre on Isstvan V.The Emperor finally explained to His loyal servants about the existence of the Imperial Webway Project. This new Human-controlled extension into the Webway would recreate the vast network of Warp Portals that had once bound together the ancient interstellar empires of the Old Ones and the Aeldari and would allow Mankind to advance at a more rapid rate, scientifically and economically, than at any other time in its history.A Human-dominated Webway would also truly unite the Imperium, preventing Mankind from ever again being divided by time and great distance as during the Age of Strife. It would also allow the Emperor to advance His plan to protect Humanity forever from the Chaos Gods by eliminating or shielding its psykers from their influence.However, the Warp Gate the Emperor had constructed and the short section of Imperial Webway passage beyond required the constant expenditure of His psychic energy to hold back the intrusion of the Warp entities who sought its ruin. At first this had demanded only a small portion of the Emperor's psychic might and so He was able to command His armies and do all that was expected of Him as Emperor. But the hideous monstrosities that ruled the Warp -- the self-proclaimed Chaos Gods -- had ever been His foes, and now conspired to subvert the Emperor's goals as they had since the day He had launched the Great Crusade.To this end they had tempted the naive Magnus the Red with a vision intended to warn the Emperor of the very plot they had initiated against the Master of Mankind, the betrayal of the Imperium by Horus Lupercal. Magnus had sent his psychic warning by means of a powerful sorcerous ritual with the aid of the Thousand Sons' other sorcerers and this sending had wreaked havoc upon the protective psychic shielding surrounding the Emperor's fragile Webway construct.The spell of Magnus not only allowed the foul denizens of the Warp entry to the section of the Imperial Webway the Emperor's secret army of adepts and Tech-priests had by then constructed, it destroyed the delicate shields the Emperor had set in place. Daemons poured into the Human-built portion of the Webway and slaughtered the thousands of Mechanicum workers present there. The Legio Custodes and Sisters of Silence were left fighting a desperate battle to prevent the Daemons from reaching the portal and breaching Terra itself.This so-called War Within the Webway proved a defeat for the forces of the Emperor after Magnus' sending destroyed the psychic shielding the Emperor had painstakingly set in place. Even though at first the army of the Legio Custodes and their supporters, the Silent Sisterhood, had managed to push back the Daemonic invaders, they continued to take many casualties.The Imperial forces had never had the advantage of numbers and each death weakened them, whereas the Daemons appeared to have a numberless horde at their disposal. Despite thousands of Daemons and their allies having been destroyed or banished back into the Warp, there were always thousands more to take their place.As the battle within wore on, the Daemons began to gain the advantage. Their assaults regularly reached deep into the Imperial defences -- more than once approaching dangerously close to the Human-built conduit that led to the Warp Gate of the Golden Throne.On one occasion a mighty Bloodthirster, greatest of the Daemons of Khorne, fought its way through the Imperial defenders to the gate itself, and only the last minute intervention of Sister Celia Harroda of the Sisters of Silence was able to stop the beast from crashing through the Warp Gate and into the dungeons of the Imperial Palace.Sister Celia confronted the huge Daemon, her presence chilling the air around it and stifling its otherworldly power, and silently she dispatched the monster with swift strokes from her blade of frost. The effort utterly exhausted her and with the final, banishing stroke of her sword she collapsed upon the threshold between the Warp and Terra's realspace, never to breathe again. The death of Sister Celia was but one of many acts of brave sacrifice by the loyal warriors of the Emperor within the Terran extension of the Webway.Eventually, after many long solar days of bloody battle, these deaths took their toll and the defenders were forced to draw back to within sight of the Golden Throne. Here they were bolstered by the psychic presence of the Emperor who appeared as a brightly burning star to those within the alien conduits.The Emperor drew on His vast reserves of psychic power and His star burned ever brighter; the Daemons, unwilling to approach the shining nimbus, were held back. The star of the Emperor gave the defenders respite enough that many were able to cross through the portal and retreat into the Imperial Palace.At first, all of the Tech-priests and workers of the Adnector Concillium were evacuated and then, reluctantly, the Silent Sisterhood and the Custodian Guard withdrew from the battle and into the Palace dungeons. The gate would remain closed to the Daemons for as long as the Emperor was able to power it from His arcane technological throne atop the golden portal.Only the mightiest of psykers had enough power to do this and even then most would be exhausted and fail in a short time. Only the Emperor had the might to keep the gate closed permanently and even for Him the effort grew more difficult as the Daemonic forces gathered about Him.Thus, in the wake of the War Within the Webway, as long as the Daemon horde threatened to breach the portal, the Golden Throne would be the Emperor's prison. The portal was closed but only the psychic power of the Emperor was enough to keep it sealed and He was forced to remain on the Golden Throne or find a suitable replacement who possessed the psychic power to maintain the shields against Daemonic intrusion.Without such a psyker of sufficient ability using virtually all of their power and mental concentration to keep the Warp portal sealed, a permanent doorway would be ripped open between Terra and the Warp, flooding the homeworld of Mankind with the Daemonic legions of the Ruinous Powers.Later the primarch Vulkan would come to the Sanctum Imperialis, where with the Emperor's guidance he installed the Talisman of Seven Hammers. This device acts as a dead man's switch which would destroy not only the Imperial Palace but also all of Terra should the Golden Throne fail. This would prevent the forces of Chaos from ever taking the Throneworld and poisoning the very heart of the human Imperium.Apparently, the core of the Golden Throne device survived the disaster caused by Magnus' intrusion, or was repaired following the catastrophe by the Mechanicum's adepts, but the Emperor's Imperial Webway Project lay in uncompleted ruins, and before the project could be restarted, the Horus Heresy erupted and the forces of Chaos laid siege to Terra itself.