The Gatekeepers are an Imperial Fists successor chapter and the leader of the five Astartes Chapters that make up the Hell Warders tasked to defend the Imperium against Chaos incursions from the 'Hellgates' dual warp storms in the Segmentum Solar which are uncomfortably close to Holy Terra..
The Gatekeeper Chapter's original name was the Golden Castellans. They were founded from Imperial Fist gene-seed sometime in the 33rd Millenia. A fleet based chapter in those days the Ramillies Class Star Fortress, Incursus Defensior, served as their fortress-monastery. They were stationed in the Gathalamor sector in M.36 which put them conveniently close to the action when the First Hell Crusade erupted from the Gates.
First Hell Crusade (110-199.M36)
Second Hell Crusade
Third Hell Crusade
Current state of the Chapter
The Grand Castellan is governor of Pylos the entire population of which, excluding the Mechanus enclaves, are counted as Chapter Serfs. The inhabitants are concentrated in the five massive hive towers of Pylos Polaris the centermost of which is the Chapter's Fortress Monastery.
The Gatekeepers are masters of defensive warfare and possibly a little to defense minded as they have a tendency to think in terms of static defenses or defensive lines. Their seat, Pylos Polaris, is an impenetrable fortress the ceramite plating the outer surface of the five Towers scarred from the futile attacks of Chaos War Bands out of the Ashaklun Gate. Their forward or offensive defense is built around the Star Fortress Incursus Defensior, similarly scarred and battered, which forms the center and control for the Gatekeeper's quadrant of the cordon around the Hell Gates. They are huge fans of heavy weaponry and their section of the Cordon is studded with space platforms mounted with guns of almost unbelievable power. The strategic goal set long ago by the First Grand Castellan is to defeat Chaos incursions in space as close to the Hell Gates as possible. Failing that to contain the incursion within the outer cordon formed by the four Hell Warder homeworlds with the support of the Templar Moline Fleet and Sector forces.
The Gatekeepers are the leading chapter of the Hell Warders. Relations between them and the other four have not always run smoothly but Peter Symeon has proved himself a tactful over-all commander with a healthy respect for the talents and opinions of his fellow chapter masters. The Hell Warders are:
The Gatekeepers' defense mindedness is balanced by the highly aggressive tendencies of the Spartiates their closest neighbor and partner among the Warder chapters.
The Gatekeepers are great builders and are responsible not only for the design and construction of the static defenses around the Hellgates but have contributed their expertise to projects throughout the Sector. In fact designing fortifications is the favorite pastime of Gatekeeper Battle Brothers who compete in the construction of marvelously detailed models of both planetary and space bourne fortresses. Once satisfied with his work, which can take years, the Gatekeeper submits his model to virtual assault by his Battle Brothers who seek to find and exploit any weaknesses in the design. Pitting their ingenuity against one another in this fashion is the form the passion for dueling implicit in Imperial Fist Gene-Seed takes among the Gatekeepers and though bloodless these virtual battles in miniature are no less fiercely fought.
Gatekeepers are also subject to dark depressions, like their moody Primarch, and thankfully rarer fits of icy destructive rage. The former affliction seems to descend totally at random and independent of any environmental cause. Brothers suffering from 'The Night of the Soul' carry on as best they can. If the depression becomes too severe or goes on too long the afflicted Brother's sergeant or captain may order him to the apothecaries for treatment which is painful but usually effective. The Cold Fury on the other hand almost always occurs in the field triggered by some enormity of desecration or atrocity on the part of the enemy. In such cases it is a group phenomena sweeping the Brothers enmass into vengeful battle in which the enemy is not merely defeated but obliterated. In is extremely rare for a Brother to fall into the Fury off the field. When it does occur he can usually be talked down by his brethren or if necessary physically restrained.
The Gatekeepers are less given to self torture than many sons of Dorn but not infrequently a Brother will be moved to sacrifice one of his hands either in penitence for some failure or as an offering to Souls of the Emperor and Primarch and those Brothers who have gone before. Brothers who express a wish to make this sacrifice are carefully screened by the Chaplains to establish the purity and soundness of their motivation. There is no shame in being denied or even in changing one's mind. The offering must be made not only in the right spirit but at the right time to have the desired effect. If the time is not now yet it will come and patience is a virtue cultivated by Gatekeepers. Brothers who have been permitted to make the offering of blood and bone and flesh feel strengthened and purified by the sacrifice and almost all will voluntarily undergo this ordeal at some point in their lives. The few who do not are those Brothers who fall in battle before they feel the need or inclination. A very few Brothers will make the offering twice. It is even more difficult to convince the Chaplains of the propriety of a second such sacrifice but occasionally they will be persuaded. Of course the removed hand is replaced by an augment so the Brother's battle readiness does not suffer.