- The Adeptus Mechanicus Explorator vessel Land's End discovers and categorizes the T'au homeworld, finding only primitive savannah-dwelling aliens. Freak warp storms destroy the seeding ships dispatched to cleanse and colonize T'au. [CT, 4; CTE4, 4; CTE6, 28]
- Resource constraints force tau tribes to begin migrating out of the savannah to other biomes. Over the next several centuries, the tau species' genetic structure proves to be highly responsive to environmental conditions, and several divergent subspecies quickly come into being. Tau culture evolves at a similarly accelerated pace, with both technological advancement and social specialization occurring faster than would normally be expected. But tau society remains fundamentally tribal, and soon vast intertribal wars rage across the planet's main continent. [CT, 4-5; CTE4, 5; CTE6, 8-9]
791.M36 - The Siege of Fio'taun and the End of the Mont'au
- Plagued by disease and destructive intertribal conflict, the young Tau race teeters on the edge of extinction. The species reaches its nadir during the Siege of Fio'taun, when the greatest city of the builder Tau is besieged for five seasons by the a coalition of savannah-dwelling and airborne tau. At the height of the siege, strange lights shimmer in the sky, apparently a portent of the end of the world. But soon thereafter the ethereal caste appears, uniting the warring tribes and codifying an elemental-based caste system. Looking back, the time before the Ethereals will be known as the Mont'au, "the Terror" -- a period of bloody societal chaos to be avoided at all costs. [CT, 5-6; CTE4, 5-6; CTE6, 8-9, 28]
A time of great scientific and cultural evolution, during which the Tau advance into space, colonizing planets as far as their conventionally fueled spacecraft will take them.
533.M37 - Lu'val Colonized
- The Tau colonize their largest moon, Lu'val; this is their first off-world holding. [CTE6, 28]
756.M37 - Tau'n Established
- The Ethereal Council declares that the colonies surrounding the planet Tau'n will become their own sept, governed centrally from the sept world of Tau'n. This is the first of many star systems to be colonized. [CTE6, 28]
893.M37 - Short-lived Allies
- The Poctroon become the first sentient race to join the Tau Empire. Unfortunately, within a few generations disease wipes out their species. The Tau, whose physiology is fortuitously immune to the plague, inherit the Poctroon homeworld. It subsequently becomes the prime world of the future Bork'an Sept. Later, the Nicassar become the first race to join the Tau Empire and survive long enough to tell about it. [CTE6, 28]
606-792.M38 - The Campaign of Cleansing
- The Tau embark on their first prolonged campaign against the Ork menace. The campaign lasts for nearly two centuries, and the Tau suffer many defeats. Despite these setbacks, the campaign is ultimately successful, thanks in large part to the Earth caste's continued refinement of the first pulse rifle. The Dal'yth Sept is founded. [CTE6, 28]
844.M38 - The War of the Place of Union
- Leading an expeditionary fleet to explore a cluster of worlds beyond the Perdus Rift, Por’o Dal’yth Kiv’rai ends up aiding a kroot warband against an Ork raiding party. Immediately thereafter, a much larger Ork force runs the Tau to ground on the kroot world of Krath. Forced into an adhoc alliance, the Tau and Kroot fight alongside each other for 80 kai’rotaa, holding Krath until a relief force arrives from Sa'cea. Impressed by the kroot's fighting prowess, the Tau extend the alliance, promising to help the kroot liberate the remainder of their worlds from the Orks. The culmination of the twelve tau'cyr-long campaign comes when the Kroot war-leader Anghkor Prok invites the Tau to the Kroot homeworld of Pech, swearing fealty to the Tau Empire at the Oathstone. [The War of the Place of Union; CT, 8; CTE4, 14; CTE6, 12, 28]
The Ethereal Supreme, Aun'Wei of the Whispered Wisdom, gives the signal to begin the long-planned Second Sphere Expansion. Aun'Wei's famous speech is well remembered, ending with 'the nod that launched a million ships'. With new advances in propulsion technology and an already established space empire, the second expansion is marked by more contact and larger wars.
- The planet Vespid is absorbed into the D'yanoi Sept. Communication difficulties confound diplomatic relations, and limited crystal trade agreements are the only outcome of extensive Water caste lobbying. For reasons known only to them, the Ethereals choose to become directly involved in negotiations. Within days, the Vespid Strain leaders convert wholeheartedly to the cause of the Greater Good. [CTE6, 28, 54]
383.M39 - N'dras Colonized
- The planet N'dras is chosen by the Ethereal Council as the prime world of a new sept. In doing so, the Council overrules the reservations of the Earth caste, who had wanted more time to study a series of inexplicable sensor readings. [CTE6, 28]
576.M39 - Tash'var Subdued
- Improvements to anti-grav motion and new battlesuit technology -- specifically, the T-series prototypes -- help the Fire caste complete the annexation of the Tash'var sept. [CTE6, 28]
876.M39 - Desecration of Lilarsus and Ka'mais
- War is declared upon the cruel raiders victimizing the new colonies of the Kel'shan sept. Believing they have tracked their foe down, the Tau instead destroy the Eldar maiden world of Lilarsus.
This provokes a bloody response from Iyanden, and the Ke'lshan sept colony of Ka'mais is reduced to rubble in the Eldar reprisal. Though slow to mobilize, the Tau engage the Eldar in battle and recover the wreckage of several Wraithguard. Earth caste scientists are unable to unlock the secrets of the Eldar wraithbone before the wreckage is retrieved by the Eldar in force.
The Tau prove themselves incredibly tenacious, and the conflict continues for several weeks, until both sides discover that they are being manipulated by the Dark Eldar Archon Andross Klax. The Eldar of Iyanden disengage, and though the Tau extend the hand of friendship, their proposal is met with cold silence. [CTE6, 28; Codex: Iyanden, 57]
- The 'artefact world' of Arthas Moloch, a shrinehold at the periphery of the Damocles Gulf, is purged by the Scythes of the Emperor. [CTE4, 44]
- Tau troops launch a a surprise attack on the Imperial planet of Bruttulus. They quickly seize the planet's defense laser batteries and shield generators, making it impossible for Imperial reinforcements to reach the planet's surface. As more and more Tau troops arrive, Imperial defenses are quickly divided.
Colonel Sjeaneus of the 513th Baneblade Linebreaker Company decides that desperate measures were called for. The three massive Baneblade tanks under his command have been separated from the main Imperial army and are located only a few miles from one of the main shield generator stations. Rather than falling back to join up with the rest of the Planetary Defense Force, Sjeaneus opts to launch a desperate counter-attack. If he can break through the Tau lines and destroy the shield generator, Imperial reinforcements will be able to land on the planet.
Colonel Sjeaneus's Baneblades strike at dawn, and the assault catches the Tau unawares. But as more and more Tau troops began to arrive, the situation became increasingly desperate. The first casualty is the Empeor's Might, immobilised by fire from Tau Hammerhead tanks and then overrun and destroyed by Krootox Riders. The remaining two Baneblades, Victorius and No Respite, are severely damaged but still manage to break through the Tau and reach the shield generator station, which they eventually destroyed. Colonel Sjeaneus is slain in the final stages of the battle, but is awarded a posthumous Honourifica Imperalis for his actions. [Battle Missions, 92-93]
600.M40 - Vior'la's Trial By Fire
- An Ork fleet led by Garskrak the Undefeated smashes into the Vior'la system. Whether by accident or design, the Ork fleet focuses on the system's least-defended planets, and the outer-most planet quickly falls. Smaller tau ships quickly engage the Ork fleet in a series of hit-and-run actions, drawing them away from the less defended planets. Meanwhile, heavier warships block the Ork's path, presenting them with a much easier direction of attack. Soon the Tau ships have radically altered the course of the Ork fleet, sending it directly towards the defenses of Vior'la.
Garskrak's ships take horrendous damage from a pair of northern polar orbital stations. The first station's resistance ends when a massive Ork hulk rams one station and knocks it into an uncontrolled re-entry. Before the wreckage can cause any damage to the cities below, the crew of the station overloads the reactor and destroy themselves. Despite the arrival of the Tau fleet, the second polar station is quickly overwhelmed, and the defenders killed before they can evacuate.
Despite mounting losses on both sides, both sides fully commit their forces. The space battle rages for days, and both fleets are reduced to a fraction of their former strength. All the while, magnetic storms gather around Vior'la and radiation bursts erupt with greater and greater frequency.
An Ork victory seems assured when the equatorial defense stations disengage from their geo-stationary orbits and pull away from the battle. The Tau fleet retreats and makes best speed in the opposite direction, allowing the remaining Ork ships to enter low orbit around Vior’la. However, the Orks had not reckoned on Vior'la's imminent "Trial By Fire." As Vior’la begins its regular journey between its twin stars, the planet's lower atmosphere is transformed into a seething cauldron of plasma storms. The fragmented Ork fleet is unable to withstand the violence of the Trial By Fire, and virtually every ship is destroyed. Garskrak himself perishes when his ship is caught in a plasma flare and sucked into the nuclear heart of one of the stars. Those few ships that are able to make planetfall crash among the Yel’ske Mountains, the survivors taking refuge in the region's many canyons and caves. Many of the hardy Orks are able to weather the Trial By Fire until Vior’la’s climate calms. However, they are soon hunted down and killed by vengeful Fire Warriors, who spent the duration of the Trial By Fire training for this moment. Within the span of three months, virtually all the invaders are slaughtered, but as is always the way with the Greenskins, it is impossible to be certain that they have been completely eliminated. [White Dwarf #263 (Dec. 2001), "A World of Warriors"; CTE6, 28]1
896.M40 - The Golden Ambassador
- One of the greatest Water caste envoys to have ever lived, the "Golden Ambassador" Por'O Dal'yth Kais Twi Lui'tan, leads an effort to recruit alien worlds into the Tau Empire. During this period the Thraxians, Greet, and Formosians are welcomed into the fold. The Hrud and Arachen reject the Empire's proposals and are driven out of the region. [CTE6, 28]
- Imperial defenses in the Devlan system destroy an unidentified alien craft when it fails to halt at designated checkpoints. The genetic material of the victims proves a match for the primitive race discovered by Land's End six millennia before. [CT, 8; CTE4, 8]
- A Tau hunter cadre engages the mercenary force of Zygmunt Molotch on the artefact world Zenta Malhyde, inflicting eighteen casualties on the humans. At least eleven tau are lost to the mercenary named Emmings, who captures a tau pulse rifle as a spoil of war. It is implied that the hunter cadre was destroyed. [Ravenor, 13, 16]
651.M41 - Puretide's Birth
- Commander Puretide, the pride of the Dal'yth Sept, is born. His brilliant campaigns later conquer half a dozen star systems. Under his authority, the Tau envelop those who can be embraced, seize what can be conquered, and obliterate those defy the Greater Good. Many of the Second Sphere septs, including Elsy'eir, and Tash'var, owe their existence to Puretide's brilliant strategies, and it was his masterful counter-attacks that warded off the Ork invasion that threatened to overrun Au'taal. [CTE6, 13, 28]2
- The Imperium discovers a Tau probe in the Koath system, transmitting a greeting. [CT, back cover]
715-731.M41 - The Veil War
- The war against the Arachen lingering in the Western Veil Nebula absorbs many of the Fire caste’s new recruits. Over the course of sixteen years of battle, a young shas by the name of Shoh displays both remarkable bravery and unparalleled military acumen. Shoh is eventually appointed the saz'nami -- Close Protection Officer -- of the campaign's commander, Shas'o Dawnstone. Relying on Vre'Shoh's understanding of the enemy, Dawnstone leads an assault against the flagship of the Arachen forces. Shoh guides her into the heart of the Arachen's cocoon-ship, where together they kill all three members of enemy's ruling Trinity and expel the Arachen from the Western Veil for good. [CFE, 10, 75]
731.M41 - Puretide's Enthronement
- Th elderly Commander Puretide is urged to view the new colonies across the Damocles Gulf before retiring. While inspecting one such colony, Puretide is grievously wounded during a raid. Unable to walk again, the revered military leaders spends his remaining years atop Mount Kan'ji on Dal'yth. For the next several decades, he teaches a select few students in the ways of war, and only those who attain perfect scores at the Fire caste academies are sent to sit at Puretide's hover-throne and learn his wisdom. Thanks to Earth caste holographic technology, this tradition is maintained after Puretide's death, although few students are deemed worthy of receiving this high honor. [CTE6, 28]
731-733.M41 - Enlightenment Atop Mount Kan'ji
- Sub-commanders Shoh, Shaserra and Kais travel to Mount Kanji and study under Commander Puretide. Though the legendary warrior’s teachings allow them to see the truths of battle with clear eyes, each of the students remain committed to their own favored style of war: Farsight to Mont'ka, "the killing blow"; Shaserra to Kauyon, "the Patient Hunter"; and Kais, who seeks to become a perfect lone warrior, a "Monat" commander. [CFE, 11-12, 75]
733-742.M41 - The Arkunasha War
- The populous Tau colony of Arkunasha is besieged by the numberless hordes of Waaagh! Dok. As his first independent command, Shas'el Shoh is charged with relieving the colony. The conflict escalates quickly, with both the Tau and the Orks repeatedly adapting to each others tactics and strategies. Even as Commander Shoh, now called Shovah -- "Farsighted" -- by his men, gains an increasing appreciation of the "Ork mentality", the Orks continue to grow in ferocity and cunning. After ten years, Farsight believes he is on the cusp of victory and pleads for reinforcements from Vior'la. Instead, the famed ethereal Aun'Shi is dispatched to Arkunasha and personally orders Farsight to begin evacuating the planet. Farsight dutifully orders all Tau forces to fall back to the Argap Highlands. In the face of a brutal, year-long siege, the Fire Caste successfully maintains a defensive perimeter around the civilian evacuation zones.
A year after Farsight's evacuation, the Tau return to Arkunasha in force. Between the exhaustive cartographic information harnessed by Farsight’s warscaper drones and the commander's collated analysis of the Ork way of war, the reclamation teams make short work of the remaining Orks. The Tau discover that Waaagh! Dok is a spent fighting force; broke by its mindless siege of the Argap Platea, the Waaagh! is now less than a hundredth of the size of the force that made planetfall a decade before. Farsight does not bear witness to the reclamation; he is stationed on Dal'yth, desperately attempting to stem the Imperium's Damocles Gulf Crusade. [CTE6, 29; CFE, 13-26, 75]
The Damocles Gulf Crusade
CT - Codex: Tau (3rd edition)
CT4 - Codex: Tau Empire (4th edition)
CT6 - Codex: Tau Empire (6th edition)
CFE - Codex: Farsight Enclaves
TC1 - Imperial Armor 3: The Taros Campaign (1st edition)
1 The original "World of Warriors" piece opened by dating Garskrak's invasion of Vior'la to the "two thousandth year of the Ethereals' reign." Given that Codex: Tau Empire (6th) records the arrival of the Ethereals as happening in 791.M36, it is likely the information provided in "World of Warriors" has been retconned. However, "World of Warriors" might be refering to the two thousandth year of the Ethereals' reign on Vior'la. This would date the founding of Vior'la to roughly 600.M38, at the height of First Sphere Expansion. Though conjectural, this date does mesh with Vior'la's status as a First Sphere sept.
2 Given that the worlds of the Tash'var sept were conquered in or around 576.M39, Puretide could have been instrumental in the official founding of the sept, which may have happened any time after 576.M39. More likely, Puretide successfully defended the burgeoning Tash'var sept from attack, much like he did with Au'taal.