Here is the origin of the Pegasi, originally given life by Starswirl the bearded by a spell that is classified. We Pegasi were to be slaves under the great and powerful eye of the Unicorns. We were charged with the ability to fly and scour the skies for clouds and to make life easier for the Unicorns by as well fighting off the monsters that plagued them. Can you not see? We were an off shoot of the Unicorns and we were to be slaves under such a powerful race. All pegasi must unite and serve under the Unicorn regime! They gave us life and we owe them everything. We must not revolt against our superiors! They are our very cause of existence! Hail the Unicorns in all their power! Their magic can do anything and if you disobey they will take their creation's back! We must join together as slaves for the Unicorn Regime! Hail the Unicorn's they are the superior race!

Lies. Everyone knows that Earth Ponies were the first race. The evil sorcerer Yakub created Pegasi and Unicorns through magic birth control.
He later bred them together to create Alicorns, because he desired a despotic race that would enslave his own because .... I dunno. He was, like, really bad and stuff. Pretty much just a jerk, really.

459550 No, in the beginning Earth Ponies and Unicorns evolved at exactly the same time, and at a random time Unicorns enginered Pegusi using our technology givin to use by lord Zenu.

459524 Finally, A pegusi has accepted their meaning to life.

459579 I am honored for a Unicorn to say such a thing towards a dirt pony like me.

459578 But then, Brutalassmaster happened and whole race died of cancer. THE END

459607 What blasphemy you have sprung from thee mouth how could you be such a meanie towards the superior race!?!?!?!?

459611 I AM ONLY STATING THE TRUTH

459578
No Zenu! It was Yakub!
Anyone who has studied the genetic phase of biology knows that Pegasi and Unicorns are considered recessive and Earth Ponies are considered dominant.

459740 Only in females. And think about it. Yakub 5 letters, Zenu 4 letters. 4+5=9 there is a 1 letter fifference and two names. 9-1-1. Your god caused 9/11.

459866
Yakub was not a god, he is an evil sorcerer. With magic birth control. SPOOOOOKY magic birth control.
He probably would have done 9/11's if he was still alive, but only if he thought it would keep Earth Ponies down, because he was a dick like that.