OOC : This is a veeeery outdated blog so I recommend not to read this. Unless you want to! ^^ This is an old blog from 2013 so be warned for continuity errors here.  So this is my very first blog so all this is about this I am going to explain if ethier the Equestrian past was once controlled by the three races of ponies before Princess Celestia and Princess Luna came along. Remember these are only my thoughts, there not canon. I thought of this when I was watching Heaths Warmings Eve. Canterlot has not yet existed and it was before Equestria was founded by the tribe leaders. Alicorns have not yet ever existed. Princess Celestia and Princess Luna started off as unicorns during the dark ages. They are under the care of Starswirl the Bearded when there parents were killed during the war between the three races of ponies. Starswirl is one of the most powerful unicorns in Unicorn history as he created 200 spells. He is like a father figure to the two fillies and he was also a mentor of another unicorn named Clover the Clever who was the adviser to Princess Platinum. Platinum's father was one of the royal Unicorn king's who didn't understand what harmony actually means. Despite the three tribes finally getting along with each other, he was the only pony who didn't like the idea because he thinks Unicorns can do anything better then the other races can. Because of the King's monarchy his subjects begin to overthrow him and banish him far from Equestria for good. Platinuim is heartbroken by the king's treachery so she begins to take his place as queen and she was the one who teaches all the ponies what harmony truly meant and soon all the ponies begin to travel to there newfound land called Equestria. After Starswirl was almost finished with his notebook, the thing he needs to finish now is making more friends. But because of his eldest ways he died before he can do so. Before his death, Starswirl has given the book to Celestia and Luna when they were just young adults. After the mournful days of the great powerful unicorn, Celestia and Luna begin to carry on by becoming Clover the Clever's mentors and she teaches them the importance of magic and when to use them. All the tribe leaders, Clover the Clever, Smart Cookie, and  Private Pansy gave birth to new ospring. Things didn't turn out right again when a powerful creature begins to attack Equestria and take over it to spread disharmony and chaos throughout the land. His name was Discord, a enternal spirit of disharmony who like Starsswirl never has friends and so he did the only thing that can be fun which is spreading his powerful chaos magic, using them on a diffrent race, the ponies. All the tribe leaders didn't survive through the whole thing and the babies have to be kept safe by both Celestia and Luna. Discord begins to encounter both Celestia and Luna and taunts them. Now he is a ruler, he exiled Celestia and Luna out of Equestria. Celestia and Luna needs to come up with a way to stop Discord so they begin to join together and thinking there is no hope, there magic begins to create the most powerful source of magic known to Equestria. It was the princess's magic who have created the two elements of harmony, the Sun and the Moon. They noticed they can use this magic to stop Discord once and for all. So they returned to Equestria to put an end to Discord's reign for good. As usual Discord just teased them by they combined there powers and rose up against him. A rainbow beam hits Discord as he just continues to shout that he will not be gone long, he will return. After that he was now in stone just before he can finished the sentence. Equestria has returned back to there glory days and because they have discovered the most powerful magic in the world, there elements sent them to a strange space full of stars and nebulae. The spirit of Starswirl the Bearded begins to congratulate them for there sucess and soon whirls of magenta and white blanket transforms them to a new diffrent and powerful race of all, the Alicorns. Soon they both are earned the title of becoming the princess's of Equestria and Equestria is now in it speaceful state. Soon the ponies begins to build a new catsle for them on the top of the mountains calling it, Canterlot. 

So yea that's my theory of where Celestia and Luna came from and its also might be where King Sombra has came from as well as being Princess's Platiuam's son. He was born with a black heart thanks to a curse of the spirit of his grandfather. He was full of hatred and fear which makes every pony scared of what he might become in the future and most ponies called him the Unicorn with a Black Heart. He wants to become as powerful as Celestia and Luna so he begins to head over to the Crystal Empire, where it was said to contain one of the most powerful magics along with the Elements of Harmony, The Crystal Heart. During the Crystal Fair that faithful day, ponies don't know Sombra was a threat and he looks like he was just a normal unicorn. Things gone horribly wrong when Sombra begins to murder the Crystal Queen and he soon assumes the throne as becoming a tyrant king who only wants just power and control. Because of the use of his own kind of magic, Dark Magic, the use of it turns him into something ugly and scary. His horn becomes red due to many use of it and his physical appearence looks like he was a demonic unicorn with sharp teeth. And that is how King Sombra took over the Crystal Empire in my own theory. So yea that's what I needed to talk about of my own story of Equestria's past. ^^ Hope you like so far.