Part 1 (one) - the Forgotten age
Equestria was little more than small groups of nomadic ponyfolk. While many groups kept within themselves (unicorns with unicorns, earth ponies with earth ponies, and pegasai with pegasai), there were a few settlements with multiple types of ponies as their populations. Such communities prospered much more than the separated ones as they didn't have to rely on trade as much.
Then one day... Darkness.
The days were barely visible and the nights were darker than ever thought possible.
The Darkness lasted centuries. Most crops died off, unable to grow without the proper light. Famine swept across the land. Settlements shrank and those who couldn't farm or hunt the adapted flora and fauna disappeared.
The few crops and animals that survived and adapted to the darkness didn't provide much nutrients, so the ponies were almost always hungry.
The time before the Darkness had just about been forgotten, only passed down through tales told by community elders through the generations.
Variations of such tales reached a young colt by the name of Sunburst. Fueled by the stories of prosperity and life before the Darkness, Sunburst wanted nothing more than to save his family from starvation. While many ponies and fillies also wanted the darkness to end, Sunburst possessed great magical ability.
And in such desperate want, Sunburst's horn lit up. It wasn't just a typical unicorn light spell, his horn lit up the surrounding area with a brightness that could rival the past sun. The light stayed for a few seconds after he stopped using the spell, as it drained his magic to hold it for too long, before the Darkness swallowed the light once more.
In the same village, another colt around the same age as Sunburst (named Eclipse) possessed the ability to move the Darkness around. While on its own this wasn't very useful, after learning about Sunburst's ability to create sunlight, Eclipse began to work with Sunburst in testing the combination of their abilities.
After perfecting their talents and increasing their magical capacity, Sunburst and Eclipse worked together to restore the land and save Equestria from the Darkness. Sunburst would create light and Eclipse would hold the Darkness back from extinguishing it. Eventually they would restore Equestria to the land it once was, pushing most of the Darkness up into space and using the sky as a barrier. The day was now bright, the sun bringing warmth and visibility and the night was no longer so oppressive.
This allowed life to return to Equestria; dormant seeds could now sprout with the light they needed, animals began to flourish with populations rising, and ponies were now able to not only survive, but grow, thrive, and progress.
And so began the Age of Light
But with the light came one issue, the sun was now much heavier with all the light it produced. When it was Dark, the sun was very light as it was dim. Before it took little effort to move the sun to create days, but now it took all the unicorns in Equestria. Such was the price to pay for a better world.
