A lot of the information around this is unclear - When exactly did our enemies show up? What is the timeline of events that led to where we are now? Here's a rough outline of my thoughts on this. We can all say that Humanity evolved in the solar system. Humanity gained spacefaring abilities, and as we arrived on Mars we found the Traveler. The Traveler moves around the universe, tending its garden, and setting up situations for life. After this meeting, humanity entered its golden age and began to gain control of the solar system at large. So, we have a good event to set here, let's call this "Contact" Now, we know that the Vex must have been in our system pre-contact. Venus and Mercury were both heavily modified by the Vex in times that long predate humanity. I expect that the Vex were in some form of stasis on Venus & Mars, and humanity "woke them up". Either that is the case, or the Vex follow the Traveler's power and use it somehow, and they appeared in the system simultaneously with the Traveler. I say this because, thanks to the Vex grimoire card fragments, we KNOW that the vex were here DURING THE GOLDEN AGE. The Ishtar Collective is studying the Vex pre-collapse. These cards give me another key idea: The Exo were created for a war with the vex. Vex 4 has the following excerpts: [quote]Up here they have to act by biomechanical proxy. No human being in the Ishtar Academy has ever crossed the safety cordon and walked the ancient stone under the Citadel, the Vex construct that stabs up out of the world to injure space and time. It's not safe. The cellular Vex elements are infectious, hallucinogenic, entheogenic. The informational Vex elements are more dangerous yet— and there could be semiotic hazards beyond them, aggressive ideas, Vex who exist without a substrate. Even now, operating remote bodies by neural link, the team's thoughts are relayed through the warmind who saved them, sandboxed and scrubbed for hazards. Their real bodies are safe in the Academy, protected by distance and neural firewall.[/quote] and [quote]"Maybe you could bring something back to now. Something you needed." Maya runs a hand across the surface of the Vex aperture, feeling it with sensors ten thousand times as precise as a human hand. These proxy bodies are limited— they crash and need resetting every few hours, they struggle with latency, they can't hold much long term memory. But they'll get better. "Or go forward and learn something vital. If you knew how to control it, how to navigate across space and time."[/quote] I believe that the Exo are the final form of these "proxy bodies". The Vex have the capability to use psychic weaponry - harmful thoughts and the like. What better to combat this type of enemy than a sentient mechanical consciousness? Perhaps Exo are humans installed into exo bodies - the war they fought was against the Vex, and perhaps they pushed the Vex off of earth and back to Venus and Mars. In any case, During the golden age, humanity developed its warminds for defense, it built its empire across the system, and began to proliferate galactically. That is, until the collapse. The Darkness shows up outside of the solar system and rapidly moves in. I suspect that the Hive was in tow, and the Hive was a pivotal part of the Darkness's attack plan. The Golden age was over, and the dark age began. After the collapse, something made the darkness leave. We aren't sure what. But the Darkness left the hive behind to keep working on the traveler. The traveler used its last breath to begin reviving guardians to protect it. It settled on earth and slumbers still. So now, in our system, we have the vex operating on mars and venus, the Hive taking potshots at earth from the moon, and humanity, & exo struggling to build up the last city and defend it. The Awoken are, well, awoken (I suspect they were in some type of seeder ship in cryosleep and were affected by the darkness somehow, and woke from their sleep changed), and many of them start to head back to earth to help. The Fallen, who must have been tracking the traveler after it left them, show up soon after to start scavenging the remains and attempting to regain the traveler. They have struck directly at earth with this one goal. The Cabal are a recent arrival in our system. Somehow they made it past the reef and the outer planets, and have begun to set up fortification on mars. I have a feeling that the Cabal are after the Black Garden. We have so little information about them though, that it is impossible to really speculate about what's going on with them. So my conception of the timeline is: Vex build planet-nodes in ancient sol system Humanity evolves, develops space flight Contact with the Traveler Golden Age begins Vex Awakening/Return Exo creation and War with the Vex War w/ Vex ends, Continued protection efforts for Sol System resume Darkness shows up, Collapse. Hive arrival, Hive remain in system Dark Age - Fallen arrive to try to reclaim the Great Machine Last city established, traveler begins to regain its strength, Awoken wake up and begin to return to earth Cabal show up to attempt for the Black Garden Present