Everyone knows the age before Celestia and Luna. Discord reigned, but what about before Discord? Does anyone know what happened before Discord reigned? Sure, there are a bunch of theories and assumptions, but no one truly knows. I'd be willing to bet that the royal sisters had something to do with it too...
Way back in the day, four types of ponies stood in an unspoken hierarchy. The alicorns, the unicorns, the pegasi, and the earth ponies. The hierarchy existed, but so did the roles of each. Everypony was happy, until their leader was cast off by ancient magic and without the leader, the clans fell apart into chaos. Event after event leads up to the current situation today, where mostly everypony is happy once again... Until HE returns.
"One Hundred-thousand will the moons go around, before the red moon rises, ready to sound. Once the chains break and the spell is broken, the time will come when the power is woken."