Spoilers for Story!

In "The Legends of Equestria: Star Swirl the Bearded"

Here is what happens.

Star Swirl writes the book that Twilight Sparkle reads (how else was the number of stars correct and so exact?)

Timeline: Pre Equestrian History (PREQHIST/ PREQ)
Then there is the Age of Construction, the first ten years after Equestria is formed (AOC)
The Age of Discord (AOD)
The Age of the Sun where Celestial rules alone. (AOS)
Modern (where Nightmare Moon is reformed, canon material)
Then there are the AU's
Star Swirls Parents live to thirty years old.
Star Swirl is born.
6 years later he performs his first spell and discovers his destiny.
Another 6 years later there is more.
4 years later, first kiss.
2 years later, Talk with Pearl
12 years later, marries.
2 years later, works on immorality spell, fails.
4 years later he perfects the spell.
Then he discovers the elements of chaos and harmony.
Then he goes on a ten year quest to the wastelands in the west, the alicorn kingdom in the east, and the frozen cold icy lands of the north.
Many years later Star Swirl takes in first apprentice, Clover.
174 years later Equestria is formed. (Therefore there is 250 years before AOC.) (Star Swirl is 220 years old.)
When Equestria is formed he contacts the parents of Celestia and Luna requesting their presence, but instead they send the two young fillies in their place to test them.
AOD- 0.
Then 30 years later after that, Discord comes, is banished.
Then shortly after (20 Years) that the sirens come and spread fear and chaos and anger.
Star Swirl banishes them, but ten years later Luna rebels and Pearl dies.
After this he does everything that he can to turn back time and bring her back to life.
But he fails, only going a week back. And that was after twenty years of failure (270 Years Old- Failure, SS; 290- Failure Again; 290-300- Isolation).
However he does find the Crystal Empire some years before that rebellion.
And it holds the promise of life for Pearl, but the ruler is Sombra and he will not help.
And the price is too heavy (and more on the history of King Somba later in another story)
Eventually however he takes on a new (second) apprentice, Stardust Shine.
Then his last and final apprentice (in the Ness AU) is Quentin Dawn.
Then modern day.