Timeline of the Warhammer 40,000 Universe - Necrons Ascendant: With the C'tan and the Necrons fighting as one, the Old Ones were now doomed to defeat. Glutted on the life force of the Necrontyr, the empowered C'tan were able to unleash forces beyond comprehension. Planets were razed, suns extinguished and whole star systems devoured by black holes called into being by the reality-warping powers of the Star Gods. Necron legions finally breached the Webway and assailed the Old Ones in every corner of the galaxy. They brought under siege the fortresses of the Old Ones' many allies amongst the younger intelligent species of the galaxy, harvesting the life force of the defenders to feed their voracious C'tan masters.In the closing years of the War in Heaven, one of the primary factors that led to the Necrons' ascendancy was their ability to finally gain access to the Old Ones' Webway. The C'tan known as Nyadra'zath, the Burning One, had long desired to carry his eldritch fires into that space beyond space, and so showed the Necrons how to breach its extradimensional boundaries. Through a series of living stone portals known as the Dolmen Gates, the Necrons were finally able to turn the Old Ones' greatest weapon against them, vastly accelerating the ultimate end of the War in Heaven.The portals offered by the Dolmen Gates are neither so stable, nor so controllable as the naturally occurring entrances to the Webway scattered across the galaxy. Indeed, in some curious fashion, the Webway can detect when its environs have been breached by a Dolmen Gate and its arcane mechanisms swiftly attempt to seal off the infected spur from the rest of the Labyrinth Dimension until the danger to its integrity has passed. Thus, Necrons entering the Webway must reach their intended destination through its shifting extradimensional corridors quickly, lest the network itself bring about their destruction.Of course, in the present age, aeons have passed since the Necrons used the Dolmen Gates to assault their archenemies. The Old Ones are gone, and the Webway itself has become a tangled and broken labyrinth. Many Dolmen Gates were lost or abandoned during the time of the Necrons' Great Sleep, and many more were destroyed by the Aeldari, the Old Ones' successors as the guardians of the Webway. Those that remain grant access to but a small portion of the immense maze that is the Webway, much of that voluntarily sealed off by the Aeldari to prevent further contamination.Yet the Webway is immeasurably vast, and even these sundered skeins allow the Necrons a mode of travel that far outpaces those of the younger races. It is well that this is so. As a species bereft of psykers as a result of the loss of their souls during the biotransference process, the Necrons are also incapable of Warp travel, and without access to the Webway, they would be forced to rely once more on slow-voyaging stasis-ships, dooming them to interstellar isolation.In the wake of these victories, the C'tan and their undying Necron servants now dominated the galaxy. The last planetary bastions of the Old Ones were besieged and the intelligent species they had once nurtured became cattle for the obscene hunger of the C'tan. To the younger intelligent species of the galaxy, the Necrons and their Star Gods were cruel masters, callously harvesting their populations at will to feed the C'tan's ceaseless hunger for life energies. The C'tan were figures of terror who demanded mortals' adoration and fear in equal measure.For unknown reasons, but probably because their individual hungers for mortal life energies knew no bounds, the C'tan ultimately began to fight amongst themselves for both sport and out of spite. Among the Aeldari, an ancient myth holds that their Laughing God tricked the C'tan known as "the Outsider" into turning on its brothers and beginning their long war for ascendancy.In the course of the C'tan's struggle against one another, whole planets were razed, stars were extinguished and entire solar systems were devoured by unleashed black holes. New cities were built by the efforts of millions and then smashed down once more. As the "red harvests" of the C'tan and their Necron servants grew thin, C'tan eventually devoured C'tan, until only a few were left in the universe and they competed amongst themselves for a long age.Eventually, even the Old Ones, who had once been defined by their patience and unstoppable will, became desperate in the face of the Necron assault. They used their great scientific skills to genetically engineer intelligent beings with an even stronger psychic link to the Warp, hoping to create servants with the capability of channeling psychic power to defend themselves.They nurtured many potential warrior species, among which are believed to be the earliest members of the Aeldari species and many other xenos races, including the Rashan, the K'nib, the Krork and many others. Terran millennia passed as the Old Ones' creations and experiments finally bore fruit even as the C'tan and their Necron servants continued to extinguish life across the galaxy.