As ever and always, all of this is canon, none of this is canon, contradictions are double canon, hail anticanon.
The Anthropocene Collapse
Industrial society reaps what it has sown in the poisoned soil of Terra. The Horsemen have come. War, Famine, Plague, Death. Two billion die in the space of a generation, more in the decades to follow. There are revolutions, civil wars, mass migrations, genocides. Governments collapse or retreat to their circled wagons. The Years of Horror have come, and there is no escape.
But, eventually, the world becomes too exhausted to keep fighting, and curls up around itself to lick its wounds. Slowly, and with great pain, it will begin to heal - never fully, and not without scars. There is no miracle, and there is no going back. No human being will ever see a live tiger again.
When the choking dust settles on this a century and a half of chaos, there are no victors. The planet is on life support. There are fascists - theo, eco, ur - there are corporate puppet-nations, there are socialist enclaves, there are newly-made hunter-gatherers, there are unclaimed and uninhabitable lands, there are the dispossessed and the victimized and the conquered. The flames of universal emancipation still burn in hidden pockets of the world, though they seem swallowed up by shadows. There are seeds to be reborn here, but it will take time to nurture them. For the time being, there is only endurance.
Colonization I: The First Years
The early years are slow and painful. Earth orbit, the Moon, near-Earth asteroids, the lunar Lagranges. Our bodies are not built for these places, but the wounds of the Collapse are so raw and fresh that we push on. Resources, energy, whatever we can get out there. Anything to take the strain off of Earth. The poor are pushed out in droves. Debts forgiven, sentences commuted, in exchange for a life in the void.
Mars is colonized for the first time, backed by corporate interests on Earth. Attempts to flaunt Terran law lead to a trade embargo, and the lack of phosphorus imports sends the colony into a death spiral, complete with cannibalism. Mars will remain dead for a while longer.
The first claims are made in the Belt. A station in Venusian orbit. Scouting missions are made to Mercury.
Colonization II: The Belt Boom
The gold rush in the Belt marks a turning point. Incalculable material wealth sent back to build up the orbital habitats of Earth and the growing colonies of Venus and Mercury.
A second attempt at colonizing Mars, this time with pie-in-the-sky genetic tweaking, is attempted and swiftly fails, though less spectacularly. It remains a sparsely-populated rest stop, unable to compete economically with the Belt or Mercury, especially now with the construction of the first solar laser propulsion system.
Preliminary expeditions and minor settlements are made in the Jovian and Saturnian systems, centered on Ganymede and Titan. Neither are large enough to be fully independent from Earth.
Colonization III: The Bust
The Belt Boom was not to last. The glut of raw materials predictably caused prices to plummet leading to a systemwide depression. Companies pull out of the Belt or go under, letting their stations go abandoned or revert to the newly-independent inhabitants. There is an exodus from the Belt sunwards and outwards - those who are left behind fend for themselves, and despite the widespread poverty there is a flowering of new Belt cultures.
Shifting power dynamics and political instability on Earth leads to a migration wave to the outer system (alongside the Belters), as well as the independence of Titan - the moon remains an ally of Earth, but now has seen the emergence of the first generation of true dataminds, who operate the colony alongside the human inhabitants.
Mars is colonized for the third and final time by backscattering corporations, as the long-neglected Red Planet is now the cheapest real-estate in the inner system. Those scattered inhabitants who had already made homes for themselves were not consulted. Eschewing any high ideals of ever making it Earthlike, craters and canyons are domed over and paraterraformed. Mars quickly gains a reputation for the poor condition of its habitats and low quality of life for the inhabitants, as the colonizing companies' desire for quick turnaround on their investment led to obvious and gratuitous abuses.
is hit particularly hard by the depression, as it had mostly been home
to the scions of Terran and Lunar wealth and had little economy of its
own to speak of. Dozens of aerostats are abandoned completely and
scuttled. Despite this, the plummeting price of colonization rights leads to new eyes looking to the planet, and during this period plans are drawn up for a
long-term terraforming project, using technologies that kept Earth alive
to eventually turn Venus into its twin.
Further out, the influx of new arrivals in the Jovian system steadily increases tensions, ultimately leading to a brief but violent conflict. Inner system company claims are dissolved and expelled, and the Jovian Assembly is formed from the migration's many disparate factions.
Colonization IV: Jupiter in Ascent
War breaks out on Mars after years of economic hardship and civil unrest. Offworld corporate interests are overthrown, though this does not lead to any real change in the way things operate (if anything, the coming decades will prove that the Martian corporate states are more brutal by far). Cyberdemocratic anarchists enter the fray and attempt a revolution in the middle of the chaos, but are ultimately cut down by the forces of the Martian Corporate Congress. Most of the survivors flee towards the outer system.
But the depression will not last forever. Jupiter has by now grown enough to eclipse Earth as the political center of the solar system. Earth makes an alliance with Titan and its dataminds in response, but they will remain as a close second, backed up by the new solar-powered laser propulsion systems.
The Martian anarchists expelled after the war, finally reach Ouranos and set up a few small colonies in its moons.
Colonization V: The Outer Worlds Period
Here then is a relatively long period of equilibrium in the solar system.
The Jovian Assembly and the Terra-Titan Alliance power blocs remain dominant.
Mars draws up plans for interstellar colonies as a way of out-competing its more powerful neighbors. It still maintains the lowest standard of living in the solar system. Ships are aimed at Proxima and Toliman.
The Venusian sunshade is constructed, and the centuries-long cooling of her atmosphere begins.
The Ouranos colonies, though small, have stabilized themselves have stabilized their small colonies.
Neptune, lacking anything more substantial than automated scientific facilities belonging to the Titanians, is taken in its entirety by the Anointed Temple of Christ, Redeemer and Conqueror. The Neptunian system is fortified before any parties can send a response
On Pluto, Jovian expeditions find the House of the Dead, as well as the first arcology of the Redoubters - both established years prior during the Bust - the former by metahumans seeking full severance from human culture, the latter by those seeking to withdraw from interplanetary society altogether in favor of deep-time social continuity.
The first tentative steps of the colonization of Kuiper Belt and Oort Cloud bodies begins, but real progress is yet to be made
A manned mission to Persephone has been launched from Saturn's shipyards.
To Steal the Names of God
And then, a miracle occurs. A cluster of dataminds in the Earth-Titan alliance complete the calculations necessary to build a hyperspace interface. They upload themselves into a vessel, activate the drive, and tear themselves entirely out of baseline spacetime. Speculation is rampant but comes to a sudden and succinct end with the arrival of Celestial emissaries a few years later.
It is important to note, that there are two schools of thought regarding the Celestials. The first and more popular is that they are indeed the descendants of those AI, having diversified and expanded over potentially millions of perspective-years. The other is that they were alien entities drawn out of hyperspace or hibernation by the successful jump drive activation. Either is viable, neither has enough evidence to clinch an explanation.
The Celestials say very little to humanity during their brief embassy: the Great Bans are dictated, templates for the manufacture of hyperspace interfaces are distributed, and they sink back into hyperspace.
There is a brief period of extreme political upheaval to follow.
Interstellar Colonization I: Boom and Bust
With faster-than-light travel dropped in humanity's collective lap by happenstance, the stars are open. As with the Belt, hundreds of parties try staking their claim and making it rich - very few of them do. Many sponsors go under before their ships even reach their destinations. Colonies find themselves having to build from scratch the infrastructure that Solsys has taken for granted for centuries. Hundreds of ships are sent out. Many fail to reach their destinations, other attempts collapse during colonization. Some are lost entirely. Some have yet to arrive. But the survivors form the basis of what would become the Core on which the expansion sphere is centered.
Formation of the CTA
The survivors of the First Wave's bust period band together under a non-aggression and mutual trade act, forming the Colonial Trade Alliance. Capital systems are Alpha Centauri, Epsilon Eridani, Tau Ceti, and Epsilon Indi. With hyperspace routes becoming more well-traveled, increased infrastructure across the colonies, and less reliance on support from Sol, the fledgling Alliance excludes the home system from its formation. This will directly lead to the Core Wars in a few decades.
A period of expansion and superficial stability, overtop a simmering and paranoid cold war between Sol and her colonies and the growing Alliance. Contact is made with several lost colonies of the First Wave. Tensions rise in fits and starts, seeming to calm down and then flare up again. Backrooms
Then, some motherfucker detonates a dirty nuke in a space station around Barnard's Star.
The Core Wars
A catastrophic conflict between Sol and allied colonies and the CTA and the most deadly war in human history. Entire colonies and some worlds are destroyed utterly - many of them minor settlements around logistically important but otherwise quiet systems along the Red Dwarf Road (as was the case in the infamous Battle of UV Ceti).
The Wars grind on for years, but eventually turn in favor of the CTA. They officially end over thirty years after the Barnard Incident with the signing of the Epsilon Indi Accords, marking the end of Sol's relevance on the greater stage.
The restructured CTA sets about solidifying its power; former Sol-alliance and independent worlds are absorbed; abandoned, collapsed, lost or destroyed colonies are reclaimed and rebuilt. This era sees great social change as well, as the stratification that had always existed within the CTA is accelerated - new technologies introduced during the wars spread into non-military applications, but limited to the corporations that form its core. Nowhere else is this more plain to see than the adoption of exultants by the Great Houses, set to lord over the baseline masses.
The Recombination is helped in part by the emergence of the first Lords of the Road and the opening of the first four junction systems of the gate network: Sirius, Altair, Vega, and Fomalhaut.
Interstellar Colonization II: Rim and Road
Warp gates are opened at Pollux, Denebola, Deneb Algedi, and Rasalhague, ushering in the age of the Road and offering easy access to the Rim. There is a flurry of colonization efforts, another cycle of boom and bust - though this time the Great Houses of the CTA are better equipped to handle the losses. The techniques this round are of quantity over quality - just enough terraforming for marginal habitability, and then sending off shiploads of undesirables. Failed colonies, or those on the brink of failure, outnumber the core worlds three to one.
With the expansion of the gate network comes greater power to the Lords of the Road, and the transition from curiosities to a major power bloc.
The Great Timeless Now
We have reached the present, for what it is worth. The CTA remains the biggest game in town but the buffer zone provided by the Lords of the Road is proving a boon for those who wish to live outside of the Alliance's sphere of influence. There are cracks in the foundations of its centuries of dominance, subversive elements gnawing away at the dam holding back the tide of history. The Firebird Rebellion burns bright. The Rim is ungovernable. New powers are emerging.
The Celestials will place an interdict on the Sol system. No ships in or out of that old, backwater system. No reasons given. Transmissions are random noise, and then silence.
The last vestiges of the CTA will fall with the activation of a quantum communication net. Thirteen trillion networked individuals will, a few months after activation, go comatose all at once, and die minutes later.
Terragen civilization will fall into a long, dark period. Warp-capable ships are few and far between. It will rebuild, in a form that no one now might predict. At some point in this era, House Flesh will institute nodes of the Zoan Archive and begin the process of pantropic importation of alien beings.
After this, it is no longer the history of humanity.