Cadia - Cadia: Cadia, officially known as Cadia Prime, was a terrestrial, Earth-like planet originally classified as the Imperium of Man's most important Fortress World by the Administratum before its destruction and consumption by the Immaterium in 999.M41.It was the fourth world of the Cadian System, and its surface contained a wide variety of terrain types and ecosystems, including frozen tundras, temperate plains, wind-swept moors and the great native axel-tree forests.Cadia guarded the only known navigable route to and from the massive Warp rift known as the Eye of Terror, a passage called the Cadian Gate. The world's dangerous proximity to the Eye of Terror made it necessary for the people of Cadia to heavily fortify the planet.Cadia was always the first target of the Warmaster of Chaos Abaddon the Despoiler's Black Crusades. These were the massive assaults the forces of Chaos launched every few Terran centuries from the Eye of Terror in an attempt to break out of the Cadia Gate and invade the Imperium proper as they did during the Horus Heresy.Cadia's natural environment was much like Terra's millennia ago, with a large ocean that covered 70 percent of the planet's surface. The land mass of the world was divided between incredibly thick pine forests of axel-trees and vast glaciers. The planet was slightly cooler than most human-settled worlds but not to the point that it adversely affected growing conditions.Settled before the onset of the Age of Strife by a branch of Humanity that eventually fell to the worship of the Chaos Gods and played a major role in the ultimate corruption of the Space Marine Legions, Cadia was re-settled sometime in the early 32nd Millennium by Loyalist Humans of the Imperium.The world's landscape was dotted by strange black monoliths comprised of the arcane substance called blackstone that were of clear xenos origin, known as the Cadian Pylons. These devices were actually constructed by the Necrons millions of standard years ago to make the world immune to the psychic energies of the Old Ones, for it was the site of an ancient Necron military base during the War in Heaven. After the formation of the Eye of Terror at the end of the Age of Strife following the birth in the Warp of Slaanesh, the Cadian Pylons acted to hold the Warp rift in check and provide a navigable passage out into Imperial space from it called the Cadian Gate.The Cadian Pylons created the unusual area of realspace stability known as the Cadian Gate near the Eye of Terror that was unaffected by the constant Warp Storms that surround that Warp rift. Cadia's location directly adjacent to the dangerous Eye of Terror made it necessary for the people of Cadia to fortify the planet to an extent where almost the entire population lived in massive fortress-cities known locally as "kasrs."Thus Cadia had an odd mix of dense urban areas and vast open tundras and other natural landscapes unspoiled by the hand of Humanity.Unfortunately, disaster struck at the climax of the 13th Black Crusade in 999.M41. Archmagos Dominus Belisarius Cawl, with the aid of the Necron Lord Trazyn the Infinite, had finally learned to use the Cadian Pylons to close the Eye of Terror once and for all. But Abaddon the Despoiler, enraged by the continued defiance of Cadia's people, gave up on his personal attempt to bring the Fortress World's defenders low with the activation of the pylons.Instead, he sent the bulk of the Blackstone Fortress Will of Eternity, badly damaged by the assault of the Imperial Fists' star fortress Phalanx, crashing into the surface of Cadia like an artificial meteor.This monstrous kinetic strike wiped out most of Cadia's defenders, destroyed the network of Cadian Pylons and tectonically destabilised the world.As the Warp and its foul denizens claimed the remains of the Fortress World, Lord Castellan Ursarkar E. Creed arranged an evacuation of the planet that saved 3 million of its citizens before the planet finally ripped itself apart -- though not before Creed himself mysteriously disappeared.The fall of Cadia represented a once-unimaginable triumph for the servants of the Dark Gods, and the Eye of Terror began to slowly expand without limit, opening Abaddon the Despoiler's coveted Crimson Path to Terra and creating the Great Rift that divided the Imperium in half.Yet among the few survivors of Cadia was a handful of Imperial heroes who had successfully escaped the destruction of the Fortress World with the aid of the newborn Aeldari faction known as the Ynnari. The combined forces fled through a Webway gate found on the ice moon of Klaisus in the Cadian System.Together, these Imperials -- the so-called Celestinian Crusade -- would forge an uneasy alliance with the enigmatic xenos that would offer a new hope for the servants of the Emperor in their fight against the waxing power of the Archenemy -- the resurrection of the Primarch Roboute Guilliman.In the wake of its destruction, the remains of Cadia in the Era Indomitus were resettled by the forces of Chaos.  It has since become a Chaos stronghold at the heart of a burgeoning new Renegade empire close to the Eye of Terror terminus of the Great Rift.The survivors of the Fall of Cadia have largely taken up residence on the Industrial World of Chaeros in the neighboring Agripinaa System in the wake of the Battle of Faith's Anchorage. They have renamed their new homeworld "New Cadia."