Some mysteries defy understanding, and sometimes even the things we think we know are untrue. Some secrets should remain untouched
-Cortana

2000 years ago there was a war, Wars have broken out here time and time again on this planet along with everything in it. Kingdoms came and went with time yet the value of peace and harmony is highly valued among the ponies who have been at the mercy of the god of chaos, discord the dragequis for a long time. But not only they but ,all the god of chaos makes treaties fragile and unpromising. Out years of meaningless bloodshed took it tole on everything, the land, the sky and the sea.

They where simply the the forms of war there use was to be used to change the world. It is unclear how they came to be, but what ever it was it did change the fate of the world for the best.