The Kinebrach, a species of simian-like humanoid aliens who co-existed with the humans of the Interex culture, ruled a large and mighty interstellar empire at this time. However, by the time the humans of the Interex made first contact with them, the Kinebrach empire was old and decaying. The Kinebrach, rather than go to war against a more vibrant and powerful species, decided to ally themselves with humanity instead.
The Eldar are unparalleled masters of the galaxy at this time. Those lesser races that dare oppose them present little challenge. Worlds live and die at their behest, for the supremacy of their great interstellar empire is beyond dispute.
The Age of Technology Begins
STC database and fabrication technology is mastered by some of the greatest scientific minds in Mankind's history and heralds a golden era of discovery, innovation and expansion. By harnessing the other-worldy gifts of the human mutantpsykers known as Navigators, Warp travel is developed, enabling starfaring voidships to swiftly travel enormous distances across space. STC systems transform the way that new human colony worlds are settled. The first Knight Worlds are established as the ancient human Long March colonies begin to flourish and new ventures are established, eventually leading to the establishment of more than a million human-settled worlds across the galaxy by the end of the period. Towards the conclusion of this remarkable era, the ever-increasing number of human psykers and an over-reliance on advanced technology such as the self-aware automata remembered only as the Men of Iron, ultimately leads to the downfall of Mankind's glorious expansion, which descends into turmoil, anarchy and war.
Emergence of the Navigators
The discovery of the psychic human mutants known as Navigators who are capable of comprehending paths through the hyperdimensional reality of the Warp and the development of Warp-Drive aid Mankind's colonisation of the Milky Way Galaxy. The galaxy is largely explored by Mankind in less than 1,000 standard years. Standard Template Construct (STC) technologies are developed to assist the spread of a common human culture and technology base across the galaxy. Late in the Dark Age of Technology, human scientists invent the Titans, the massive robotic walkers that are used in both warfare and for non-military labour activities such as extreme environment mining.
The Great Diaspora
During the span of the Dark Age of Technology, humans seek to remake the galaxy in their own image, including seeding many naturally habitable and terraformed planets with familiar Terran plants and animals. In many cases, these lifeforms eventually replace the new colony worlds' native ecosystems, leaving the human-settled galaxy with an unusual level of biological homogeneity.
Creation of Thinking Machines
Building on the work that created the Titans, human cognitive scientists develop the first truly artificially intelligent robots later remembered in human legend only as the Men of Iron. The Men of Iron are intended to serve humanity in peace and war, but they rebel against their human masters in a conflict spanning the whole of human-settled space that is even greater in scope than the later Horus Heresy, leaving trillions dead. The development of true artificial intelligence is outlawed on all the worlds of Mankind after this conflict -- a ban that is still religiously upheld by the Imperium of Man in the 41st Millennium. The war with the Men of Iron badly disrupts the unified interstellar human society that had grown up through the millennia of the Dark Age of Technology, having caused severe disruption to the economies and societies of thousands of human-settled worlds. Not long after the robotic revolt is put down, the first truly potent human psykers begin to emerge in the populations of many worlds. Unable to fully control their powers, they often become possessed by the daemonic entities of the Warp, unleashing full daemonic attacks on many worlds and devastating societies still reeling from the battles with the Men of Iron. This initial psychic awakening for Mankind marks the beginning of the Age of Strife.