Timeline

This is a proposed timeline.

BE: Before Eruption - AE: After Eruption

~10-100 million years BE: In close succession: three meteorites hit the Earth and two more crash on the moon. The direct and indirect effects of the incident bring about the extinction of a big number of species in the following period. The ones that survive, though, will eventually populate the planet in full, returning life to it. The meteorite in the ocean will later start poisoning the water around it and mutating the residents of the sea. Even later hints of it will wash off in the western continent's coast. At this point, it's unclear when exactly.

~350,000 years BE: Homo Sapiens first appears.

~100,000 years BE: The land surrounding the second meteorite crash site is first inhabited by humans. They will slowly come under its influence.

~4000 BE: The abilities of the special bronze found in the land neighbouring the second crash site are first discovered (although not by the broad public).

~300 BE: At the third meteorite's crash site, in the southernmost island, alchemy using yellowstone is developed.

1 AE: The Volcanoes erupt. Much destruction ensues. You know the story. At that point, civilisation should be at about an early medieval (or antiquity) phase. After the isolation, separate civilisations advance or regress in their own pace and direction.

1-653 AE: A mild Ice Age comes upon the planet.

649 AE: Southern-Continent Ships (re-)discover the Northern-Continent. Limited contact is established in the next years.

703 AE: Youmoto finally resolves its internal conflicts with the rivaling nations of its continent ("China", "Korea") and having established itself as the reigning power in its land mass, it now looks to the rest of the world.

741 AE: The first official contact between non-central landmasses occurs when a Youmoto aircraft lands in Northern-Continent's land.

745 AE: The first global congress is held in "Junction", with representatives hailing from all major countries present, to discuss world politics to maintain the peace and stability of the planet.

874 AE: The first Grand Tournament of Magicians is held and our story begins.

Bonus:

Rough Timeline

Written at a different time. We can hopefully merge the two later. This is more verbose, though, so its information might have to be transferred in the relevant pages.

Alright, quick flashback possibly some tens of thousands years ago. Three meteors fall on the earth, some mayhem might ensue, the dinosaurs die, life continues. The end.

But well see the issue the meteors weren't exactly the most normal meteors. Three of them strike. One on the Southernmost Island, one right into the "Egyptian" area and one at the south of the western ocean we see on the map.

What's the result? Firstly, a lot of fish die. These three meteors contain materials on them that we shall call pre-medstone for now. These are just as toxic as medstone, so the meteor in the sea kills anything in a long radius around it.

What happens after that? Flash forward a few years, and those fish and other sea creatures at the edge of the effect of the, let's call it blackstone right now, the ones who've just barely managed to survive despite the adverse situation begin to mutate. Eventually terrible monsters are formed. The Darkness of the Sea is born. A pitch black darkness polluting the sea, killing anything it touches, eating anything it doesn't kill, mutating anything it doesn't eat. From the perspective of the people living in this world, it's a fairly ill-documented phenomenon and people don't really exactly know what it is. They only know to fear the legend of the Darkness of the Sea and steer clear of it.

Flash forward: people move close to the "Egyptian" pre-medstone, what colour shall we make it? I'd say red is fine, but redstone is already taken by Minecraft... Anyway, the thing that's there starts causing a shift to some of the people living there.

Flash forward: a bit of blackstone washes off to the shore of Medieval Land. Might later cause some magical creatures to rise there, but just few enough for them to remain mostly in the realms of legend. Flash forward: the hints of somethingstone that have found themselves in "Arabia" (and maybe "Persia") cause some spiritual beings' form to alter and acquire a physical form of fire and somethingstone. Those are Djinn. Flash forward: "Arabic" people learn they can use a copper-like metal that contains somethingstone to make bronze that binds the Djinn to their physical form and they use it to make the Djinn obey them... if they can catch them.

Flash forward: The people in the Southernmost Island discover they can use an amber-coloured substance (let's call it yellowstone in honour of the supervolcano) they find in the volcanoes to perform alchemy. Not the flashy kind like you see in FMA or F&H. Just turning one material into another, probably with a lot of trouble (pre-medstone materials are generally weaker than medstone). They might call it philosopher's stone. After all we've already got that stone theme set up. Or they might reserve the name for medstone, which also allows them alchemy, but is better at it.

Flash forward: Boom! The volcanoes explode. Chaos. Devilsrain. Bad stuff (also RIP Southernmost people, most of them die). Most of the Yellowstone reserves of Southernmost island are blasted off into the air and combine with the Black Goo of the northern volcanoes to make medstone. There may or may not have been an involvement of the spirits of the land who awoke in the volcanoes and incarnated as the ash and smoke titans who collided. We don't really know.