Timeline of the Warhammer 40,000 Universe

This article relates to events in the universe prior to the late 41st Millennium in the Warhammer 40,000 setting. throughout this article, comparative references to dates will be with respect to the approximate time period 990.M41 to the end of 999.M41. This is the time period in which the perspectives of the Imperium and the Eldar are particularly relevant.

Pre-History
The Slann*needs review and references*

The Slann are an incredibly ancient race in the Galaxy, pre-dating all other known corporeal beings. The Slann are commonly thought to have been an advanced race in excess of sixty million years ago and are responsible for the creation or advancement of most of the currently active species.

The War in Heaven*likewise*

A conflict arose between the C'Tan, immensely powerful, incorporeal beings existing (almost uniquely) in the material universe, and the Slann. The Slann, being physically weak and few in number but mighty in intellect and power, created the Eldar race and stimulated the genesis of the Eldar Gods as (originally) demigodly beings who fought alongside their mortal charges. In response, the C'Tan fashioned themselves corporeal avatars known as a Necrodermis from a metal-like substance and enslaved the Necrontyr race by bonding them with armoured shells, which became known as Necrons.

Eventually, the C'Tan were forced to withdraw, hiding for many millions of years while the Necrons hibernated on forgotten 'Tomb Worlds' inside massive complexes, tended by artificial mechanoid constructs and only occasionally disturbed by the probing of younger race's explorations.

Human Ascendancy
The Stellar Exodus

A poorly-understood period of history which is generally accepted to be the majority of mankind's initial forays into space and the genesis of most of the oldest Human colonies. This period is generally understood to lead into the

Dark Age of Technology

Again much of this era of human history is mysterious, but what is known (largely from the works of Keeper Cripias) is that a group known as the Golden Men relied on the works of the Stone Men in order to create a fantastically prosperous society, but one devoid (by later Imperial standards) of spirituality or piety. The Stone Men are known to have created a third group, the Iron Men, postulated to be androids in order to assist them. The Iron Men became uncontrolled, and a cataclysmic conflict broke out, resulting in a partial Malthusian Catastrophe.

The Age of Strife


 * merge the current AoS in here*

The Fall of the Eldar

 * insert blurb on the Fall*

The Great Crusade
The Great Crusade

The Tyrannic Wars
Tyranids

Hive Fleet Behemoth

The first recorded encounter with the Tyranids occurred in the Eastern Fringe of the Galaxy and was documented in reports from the planet Tyran. An Adeptus Mechanicus Explorator station at Tyran identified a collection of worlds in the area that had been stripped bare of their biomass and atmosphere. The station was subsequently attacked and consumed. A year later, an Imperial Inquisitor named Kryptman, who received information regarding the attack, arrived on Tyran to investigate. After searching the planet he chanced upon a data codex hidden deep within Tyran's crust, which contained information about the invaders

The information collected by the Explorators on Tyran allowed Kryptman to identify the pattern of attacks and predict the course of the hive fleet. However, these predictions came too late: several more civilisations were wiped out, largely because astropaths could not send psychic requests for help because of a phenomenon known as the "Shadow of the Warp"- somehow, the presence of a hive fleet near a planet stops psychic communication, which is the primary method of interstellar communication used by the Imperium.

The Tyranid force, dubbed "Hive Fleet Behemoth", cut a swathe into the Ultramar sector, the realm of the Ultramarines Chapter of the Adeptus Astartes. Undeterred by the Marines' strike fighters, the fleet reduced Prandium, the garden world once known as the "Jewel of Ultramar," to bare rock.

Eventually, Chapter Master Marneus Calgar mustered his entire force for a last-ditch defense of the Ultramarines' homeworld of Macragge. Here, during the Battle of Macragge, the hive fleet was completely destroyed. However, the Ultramarines suffered heavy losses, losing their entire First Company in a last stand at the northern polar fortress. [edit]

Hive Fleet Kraken

The second wave of Tyranids to fight against the Imperium was known as "Hive Fleet Kraken". Instead of throwing one mass of troops against the human armies, this swarm split into countless smaller fleets, each one enveloping whole systems before reinforcements could arrive. Kraken was finally brought to battle on a grand scale at Ichar IV, a Hive World, in 993.M41. The brunt of this attack was borne by the Scythes of the Emperor and Lamenters chapters of the Space Marines and the Eldar Craftworld Iyanden, all of whom suffered very heavy losses. According to Lieutenant Kage of the Last Chancers penal regiment, the Imperial Guard "Lost over a million men at Ichar IV", though this may serve simply to illustrate in a very broad sense the scale of the battle, as numerically speaking a million soldiers is not a great burden for a Hive World. Kraken was not fully destroyed though, and split into several splinter fleets. There was little respite for the Imperium after Kraken's near destruction as a new hive fleet emerged soon after. [edit]

Hive Fleet Leviathan

The third wave of Tyranid attacks, "Hive Fleet Leviathan", appeared from below the galaxy and attacked from two points, cutting off large portions of the galaxy from reinforcements. In order to buy some time, the Imperium, under the command of Inquisitor Kryptman, attempted to redirect the attacks of this fleet towards the Ork-held worlds of the Octavius system. While the plan was a success, the Tyranids have since been steadily working their way through Ork space, suffering massive losses, assimilating everything that stands before them. The Imperium has bought itself a century at least to prepare for the next attack, but there is no telling how the Tyranids may evolve thanks to the newly-harvested Ork DNA.

Leviathan also attacked around the same time as Kraken, making both fleets difficult to deal with as one or the other would provoke some sort of uprise or invasion. To date, Behemoth is the only tyranid hive fleet that did not utilize the "tendril" tactic, suffering the consequences.

Leviathan, inevitably in the end, was immobilized and destroyed, thanks to the Chamber Militant of the Ordo Xenos, Deathwatch and the Ultramarines Fourth Company (Read Latest Codex Space Marines-An Eternity of War).