Istrouma - Istrouma: Istrouma is an Imperial Desert World and the Space Marine Chapter Homeworld of the Tome Keepers Chapter. It is located in the Caracros Sub-sector of the Macharius Alpha Sector of the Segmentum Pacificus. Its climate is arid and dry, marked largely by volcanic, desert and mountain biomes.Istrouma exists in a state of perpetual suffering. Scoured by baleful energy from the system's white dwarf star, the planet's surface is heavily irradiated, save for a single large continent that survives on the dark side of the world away from the star's harsh glare.In addition, the planet's erratic orbit around its star and the gravitic pull of its two moons create tectonic upheaval that alternatively birth new mountain ranges or regularly tear open the crust of the planet to reveal seas of molten lava.Istrouma is sparsely inhabited by Imperial standards. Small colonies of miners exist out in the barren wilderness and deep beneath the mountain ranges, but the majority of the world's population lives on the one, easily inhabitable continent.The planetary capital is the city of Niveneh, beneath which can be found the vast libraries of the Istrouman people. The fortress-monastery of the Tome Keepers is located near Istrouma's northern pole atop the Zaatos Mountains. It is heavily shielded to protect it from the ambient radiation.The inhabitants of Istrouma live very short lifespans due to the planet's harsh conditions and the high levels of ambient ionising radiation, rarely living beyond the age of thirty standard years.Though the people of this world once had longer lifespans in ages past, over the millennia their technological level and thus their average life spans had declined. In effect, progress in their society is painfully slow due to people dying at young ages before they can reach their full potential.This high mortality rate forces the Istroumans to learn their chosen crafts quickly so that they can contribute to society before they expire, and there is precious little time to pass on that knowledge from master to apprentice, from one generation to the next.For this reason, in place of oral traditions and effective mentorship, the people of this world maintain written records of everything. When death claims an Istrouman, these detailed records enable their successor to continue where they left off, if only for a few short standard years before they too must pass on the torch to the next scientist, artisan or strategist in line.Each Istrouman records their deeds for posterity in their own personal or family book, essentially like a journal. This, combined with their life's work and their quest to record every bit of knowledge possible, creates a colossal amount of information worthy of filling many libraries.Once full, these completed tomes are then stored beneath the surface of the planet's capital within Istrouma's great archives.When the Ultramarines Successor Chapter designated number 281 first landed upon Istrouma's surface in 567.M32, they were welcomed as heroes of legend. After being informed of the tragedy that had stricken the Istroumans and their greatly shortened lifespan, the Chapter was moved beyond words.The Space Marines were further honoured with the stewardship of the Istrouman people's most revered possession -- the vast libraries they maintained beneath the surface of the planet's capital city. This vast library was almost a city in its own right, and it contained millions upon millions of books, dataslates and cogitator information terminals. Upon those shelves lay the history of aeons.The Astartes graciously accepted this most profound gift and swore a solemn oath to protect it forevermore. Taking the name "Tome Keepers", they have proudly borne their Chapter name ever since.