Thunder Kings
Summary of Legion XXI
Generalists, Repentant, Not!Celts Even-tempered, proud, and noble. The Thunder Kings took the Heresy badly, with more than half of their legion fighting for Hektor and his Traitors. They are now repentant, trying to quietly clean up their mess. They are renown for taking a cautious, methodical approach to warfare, and favour combined armed tactics over any single focused doctrine.
Legion Tactics
Legion Equipment


It is rumored that the Thunder Kings claim descent from similar genetic stock as the Thunder Warriors of old, and are simultaneously the subject of interest and revile as a consequence. They are larger than the majority of other Astartes, yet exhibit no other outward signs that’d betray such lineage.
Legion Doctrine
It is rumored that the Thunder Kings claim descent from similar genetic stock as the Thunder Warriors of old, and are simultaneously the subject of interest and revile as a consequence. They are larger than the majority of other Astartes, yet exhibit no other outward signs that’d betray such lineage.
Appearance
Youth
The Coming of The Emperor
The Great Crusade
The Heresy
During the Heresy, seven of the twelve tribes abandoned the Emperor and Brennus, heading towards Terra to assist Hektor Cincinnatus. Four of the remaining tribes set out in the same direction, assisting loyalist forces in various skirmishes and battles in the vicinity of the Sol system. It would be almost a year before Brennus lifted himself from Alessia, burning the world behind him, and took his last remaining tribe--his personal one--with him to Terra.
Post-Heresy
In the modern era, the tribal structure has been disbanded, and the Chapter no longer recruits from a single world. The loyalist tribes were instead broken off into their own individual Chapters, and are known to maintain close ties to the original Thunder Kings--who are all of Brennus’ original tribe. The Chapter is now mostly Codex Astartes adherent, at least with regards to organization, though it still maintains more Marines than is considered standard--owing to its extended garrison duties in many locations. Most notable is still their fondness for unified tactics, and it is unsurprising to see the Thunder Kings working alongside their brother chapters or with regular Imperial forces in the conduct of a combined front against a greater enemy.
Following the voluntary burning of Alessia, the Thunder Kings instead now recruit from a multitude of planets spread out over a gauntlet of stars known as the Soctis Cluster. With several black holes orbiting the periphery of the cluster, the habitable planets scattered throughout the Cluster are habitually bombarded by erratic seasons, exotic radiation, and altogether experience harsh conditions. It is from these worlds that the Thunder King recruits are drawn, with a permanent garrison maintained on each one.
Other
Notable Figures
Garrick Hammerhand, Foeseeker and Captain of the Colgrist Tribe of the Thunder Kings
After the unification of the twelve tribes of Alessia each chieftain was given voice as lord of his people. This tradition forged a unity previously unknown to the world, one which Brennus carried with him to the stars when he rejoined the Emperor. Each grand company of the Thunder Kings would draw from one of the great tribes for recruits, and as before, the chieftains, now captains over armies of astartes, served as the council for their primarch.
Garrick was one such captain, drawn from the Colgrist tribe of the far southern forests. His rise to authority had not been a meteoric one, but rather a steady rise through the attrition of war. His leadership and combat skills were well respected, but promotion by circumstance other than the death of his predecessors never came due to his clash with the patient ideal of the legions ways of war. Garrick was a bold man, favoring decisive action and swift, powerful deployment of the forces at his command. His peers view his command as a reckless one that risks too much for little gain. His retort has always been that fortune favors the bold, and only those who dare will know the glories of victory. To his credit, Garrick's style of leading the charge has galvanized a loyal following of troops within his tribe, forming a solid spearhead that faces the foes of mankind with unflinching resolve and fury. Upon his elevation to command of the 5th grand company of the Thunder Kings, the reputation of his troops was one of great renown and open mindedness, with a willingness to drive home unorthodox and aggressive tactics to gain victory.
Ultimately, the loyal following Garrick possessed would be his only saving grace. When the treason of the warmaster was discovered, so too were the roots of cancer that gnawed at his company. The drive for glory had become brazen in their ranks, spurred on by the success of the equally brazen captain. Yet his loyalty would have prevented them from testing their prowess against the most dangerous game of all: rival astartes. The 5th grand company had been long poisoned by the whispers of outside forces. Proud hunting tradition founded in the forests of Alessia had been twisted by the subtle works of the Children of Armok and their proxies; now the men sought to test themselves not for the edification of their tribe and Emperor, but to vaunt themselves above their kin. Garrick had been seen as the embodiment of this, but his fidelity to his primarch would harbor no treason.
In the end the captain of the Colgrist found his position usurped and his ship torn by a sudden, violent mutiny. His personal guard and loyal men from his days as a lesser officer quelled the fighting, but only after five hours of ceaseless slaughter as brothers in arms fell upon one another. Such bitterness only grew worse when his ship, the Astral Huntsman, was fired upon by the remaining vessels of the company's fleet. Word of the failed uprising had reached the other vessels where similar mutiny had ended swiftly in the traitors favor. Shocked and enraged, Garrick had to be restrained by his men, lest he command his ship on a suicidal final stand. Better, they reasoned, to flee and give word of their losses than to leave Brennus short a captain and the vital news. Fleeing from the treasonous Colgrist fleet, they rejoined with elements of the still loyal Thunder Kings. Swearing vengeance upon the grave breach of faith his men had committed, Garrick joined the marines bound for the Jovian campaign and became the Hammer of Brennus, instrument of the primarch's wrath.
The Hammers of Brennus
The Hammers of Brennus were formed in the early days after the Heresy from survivors of the loyalists that fled annihilation from the traitor tribes. They were added to the roster of one of the tribes decimated in the fighting late in the Heresy to bolster their numbers, the chapter now forms a vengeful, vindictive offshoot of the more temperate parent legion. The Hammers of Brennus hold an eagerness to exact a toll of blood and violence on those who turned from the Emperor's light, and hold incredibly strong ties of brotherhood within their own ranks as survivors and warriors, which extends to the rest of the Thunder Kings and their child chapters. Among the Thunder Kings, it is the Hammers that are first to fight. They respond swiftly to calls for aid (especially from forces facing the Archenemy) and deploy using an extensive number of drop pods form a sudden, explosive presence on the battlefield. From the bitter close combat of planetfall a landing zone is swiftly secured for the rest of the chapter's forces to deploy, allowing a multitude of heavier supplies to be ferried into the hot combat zone under extensive gunship protection. This vanguard force swiftly shifts from a defensive posture to an offensive one once the beachhead is secured. As reinforcements arrive, the chapter turns to a highly aggressive force focused on harrying the enemy and ensuring superiority of mobility by assaulting air and rapid attack assets. This in turn frees gunships from convoy detail, allowing for even greater reach. Ultimately, the Hammers turn the crucible of deep strikes and rapid assault into an art, one which marks the bane of slower, more cumbersome foes. Given their close ties to their imperial allies, it is safe to assume that when Brennus' hammers make landfall, relief is soon assured.