Ultramar - Core Worlds: The Ultramarines are unique in that, unlike their fellow Astartes Chapters, for ten standard millennia they controlled nine major habitable worlds, rather than a single Chapter planet, star system or fleet. Collectively, these thirteen star systems and the recent additions made to the realm by the command of Roboute Guilliman in the wake of the Plague Wars are known as the Realm of Ultramar, a sub-infeudated autonomous region of the Imperium of Man, with Macragge as the capital world.Macragge is a cold and rocky world with large, inhospitable polar regions, though certainly capable of sustaining Human life. It is home to the Fortress of Hera, the Ultramarines' fortress-monastery. Ultramar is located in the galactic southeast of the Eastern Fringes near the galactic rim. The Asuryani Craftworld Iyanden has been sighted in this sector and the expanding T'au Empire] is also nearby. Twice Ultramar has stood in the path of a Tyranid Hive Fleet and the Tyranid threat in the Eastern Fringes remains strong.The core worlds of the Realm of Ultramar in the Era Indomitus include:Andermung - Capital world of the southern Tetrarch.Calth (Cavern World / Civilised World) - Calth is an airless Civilised World whose inhabitants live in underground cities where the deadly light of Calth's blue sun cannot reach them. The caverns of Calth are constructed on such a huge scale, and with such grandeur, that they are as light and airy as any city of Macragge. Of all the local worlds, Calth is the most specialised, for although its people grow vast quantities of food in nutrient vats, they prefer to import most of what they eat from the neighbouring system of Iax. Calth is famous for its orbital shipyards, which provide the spacecraft used by the Ultramarines as well as civil and military craft for wider use in the Imperium. Calth was the site of a major battle during the Horus Heresy, in which the Word Bearers Traitor Legion attempted to destroy the Ultramarines to prevent them from reaching Terra in time to aid the defence of the Imperial Palace from the forces of Chaos.Espandor (Cardinal World) - Most distant from Macragge is the world of Espandor, a planet of extensive forests whose major cities are confined to the westernmost of its two continents. Espandor is a secondary settlement whose people are the descendants of explorers from Macragge and hold considerable pride in their rugged existence. Tradition has it that Espandor was settled during the Age of Strife by traders blown off-course and subsequently stranded by Warp Storms. It is the least densely populated of all the worlds of Ultramar.Gantz (Forge World) - Gantz is the moon of Konor and an ancient Forge World that produced much of the Ultramarines Chapter's equipment. It was also the home of their allied Titan Legion, the Legio Praesagius, which had been devastated by the Traitor Legions during the Battle of Calth.Iax (Agri-World) - Iax is sometimes described as the Garden of Ultramar. Its climate and fertility have made it one of the most naturally productive worlds in the Imperium. The inhabitants have harnessed the planet's inherent verdancy, covering its surface with well-ordered farms and cultivated woodlands. There are no large cities on Iax, but many small towns dotted over the landscape, connected together by an efficient system of fast hydroways. The oldest and most urbanised area of Iax is the ancient city of First Landing, whose citadel has withstood the barrages of invaders over the centuries. Legend has it that Guilliman came to Iax many times, and that he treasured the world almost as much as his beloved Macragge. Iax served as a "Hospital World" for Ultramar during the Plague Wars, but was eventually overwhelmed by a daemonic invasion led by the Great Unclean One Ku'gath. Following the final battle of the Plague Wars between Guilliman and the Daemon Primarch Mortarion, Iax has been reduced to little more than a ruin in the wake of the Death Guard's use of a Virus Bomb to cover their withdrawal off-world.Konor (Research Station) - Konor is one of the founding worlds of the Realm of Ultramar and has long played host to a large population of the Adepts of the Machine Cult. It is currently the capital world of the northern Tetrarch. It was formerly an officially chartered Forge World of the Adeptus Mechanicus but now bears only the designation of Research Station due to internal Mechanicus politics. Its moon of Gantz is still officially recognised as a true Forge World. Konor shares a common culture with the rest of Ultramar, but technically is independent of the Lord of Ultramar's rule as it owes allegiance instead to the Fabricator-General of Mars. However, Konor often relies upon the Ultramarines for its defence and the products of its manufactoria are mostly intended for use by the Chapter.Macragge (Civilised World) - Macragge serves as the Chapter homeworld of the Ultramarines Chapter of Space Marines and the capital of the Ultramarines' Realm of Ultramar. Macragge itself is mostly bleak and rocky, with more than three-quarters of its land mass formed from mountainous upland almost entirely devoid of life. Macragge is famous as the site of the invasion of the Tyranid Hive Fleet Behemoth, which was repelled by the might of the Ultramarines at the Battle of Macragge. Macragge, the Ultramarines' homeworld and location of their fortress-monastery, the Fortress of Hera, and the great planetary capital Macragge Civitas, is just one of the 11 original worlds in the Realm of Ultramar. Macragge itself is mostly bleak and rocky, with more than three-quarters of its land mass formed from mountainous upland almost entirely devoid of life. The people of Macragge do not live in this inhospitable region, but the fortress-monastery of the Ultramarines is built here upon a craggy peak surrounded by impenetrable mountains. Within this mighty fortress, inside the vast Temple of Corrections, is the shrine of the Primarch Roboute Guilliman himself. This is where his body once sat before his resurrection in 999.M41 upon a huge throne of ornately-carved marble. He was preserved near death by a stasis field impervious to the decaying effects of time. This was once one of the holiest places in the Imperium, and thousands came from all over the galaxy to look upon the face of the ancient Primarch.Parmenio (Training World) - Parmenio is an Ultramarines Training World used largely for the recruitment of the Chapter's Neophytes.Prandium (Dead World) - Prandium once teemed with life. Settlers from Macragge established a colony on the planet after the Horus Heresy. Thanks to a mild climate and fertile virgin environment, the people of Prandium soon prospered. The planet in time became the most beautiful jewel of Ultramar, a world of remarkable prosperity and an incredibly rich native flora and fauna. Unfortunately, Prandium's diverse biosphere was destroyed by Hive Fleet Behemoth in the First Tyrannic War. The lifeless planet is now reduced to bedrock, its atmosphere blown into space by the ferocity of the Tyranid attack.Protos- Capital world of the western Tetrarch.Talasa Prime (Fortress World) - Talasa Prime is the domain of the Inquisition's Ordo Xenos and serves as an Inquisitorial Fortress World. Talasa Prime is most notable for housing the headquarters of the xenos-hunting Deathwatch, the Chamber Militant of the Ordo Xenos. It is here that Space Marines are recruited from all different Chapters, trained and equipped as Deathwatch Kill-teams for service against the various alien menaces that lurk throughout the galaxy. The lords of Talasa Prime's Deathwatch keep their own counsel, though their wars against the Tyranid Hive Fleets and the Tau race have proved critical. The Watch Fortress also recruits, trains and equips Kill-teams composed from the Ultramarines, Scythes of the Emperor and Lamenters Chapters for service against the Tyranids.Talassar (Ocean World) - Talassar is a planet of storm-tossed seas and rocky islands whose single continent is known as Glaudor, which was the site of a major battle between the Ultramarines and invading Orks immediately after the Horus Heresy. This is the homeworld of the famed Ultramarines hero Cato Sicarius, commander of the Ultramarines 2nd Company.The Triple Worlds (Quintarn, Tarentus and Masali) (Agri-worlds) - These small planets of the Masali System form a triple world combination orbiting around a common centre of gravity much like Terra and Luna. Gigantic horticultural cities cover hundreds of square kilometres, capturing precious water in wind traps and storing it in massive underground tanks. The cities of the Three Planets are enclosed by gigantic domes under which flourish forests and gardens as lush as any in Ultramar.Vespator - Capital world of the eastern Tetrarch.