Ultramarines 4th Company - Guardians of the Eastern Fringe: The Ultramarines have always held the Eastern Fringes of the galaxy in the vast Ultima Segmentum against the forces of darkness that threaten the Imperium from beyond the Halo Stars, and the 4th Company has a special hatred for the savage xenos invaders known as the Tyranids. Rapacious, extra-galactic predators, these relentless alien killers consume all before them in their quest for bio-matter to feed the ever-hungry biological factories of their Norn-Queens.The first Tyranid hive fleet, code-named Behemoth, smashed into Imperial space in 745.M41 and descended upon Macragge in a fury of talon and claw. Forewarned of the coming xenos danger by the Inquisitor Kryptman, the Chapter Master of the Ultramarines, Marneus Calgar, stood ready to face the deadly aliens, but nothing could prepare his warriors for the sheer horror of what was to come.Commanded at this time by Captain Idaeus, the 4th Company fought at the forefront of the invasion and were instrumental in the destruction of several of the larger Tyranid vessels. At last the invasion of Hive Fleet Behemoth was repulsed, but at terrible cost; the entirety of the Ultramarines' Veteran 1st Company was wiped out defending the northern polar defences of Macragge and many great heroes of the Astartes met their end. The Ultramarines had won the First Tyrannic War, but Kryptman assured Calgar that the Tyranids would be back.With the destruction of Hive Fleet Behemoth, the Ultramarines set about consolidating their hold on the interstellar Realm of Ultramar. Many of their best and bravest warriors had fallen to the Tyranids, and with their strength thus depleted, many other alien and piratical raiders took advantage of this lapse in security and launched their own raids throughout Ultramar to sack worlds previously unassailable.Thus it was that the 4th Company -- which had been at full strength when the Tyranid fleet attacked – had come through the war with the fewest casualties, and were thus the first called upon to help liberate Vorhn’s World, a Shrine World of the Ecclesiarchy in a neighbouring sub-sector.The Ork Warlord known as the Arch-Maniac of Cabela had seized the world, enslaving its population and defiling the holy temples of the Emperor. Such barbarity could not be countenanced on such a holy world and thus the 4th Company was tasked with its liberation. Idaeus once more led his warriors into battle, using a combination of rigid adherence to the words of the Codex Astartes and an uncanny ability to adapt to rapidly changing battlefield conditions to circumvent many of the Ork strongpoints and destroy the most vital elements of their defences.With much of their energies spent hunting down the Space Marine raiders in their midst, the Orks were unable to repulse the massed tank companies and regiments of the Imperial Guard's Jovian Hussars who overran the Greenskins with an unusually low casualty rate. It was during the cleansing of Vorhn’s World that a young Space Marine named Uriel Ventris first came to Idaeus' attention.Descended from the legendary Lucian Ventris, who had died fighting the Tyranids of Hive Fleet Behemoth beneath the polar defence fortress 180 years before, Uriel displayed an exemplary courage, even amongst warriors for whom heroic feats of bravery were the norm. Taking command of his squad when his sergeant was killed by an Ork warlord, Uriel displayed the qualities that would one day lead him to command the 4th Company itself.