KPDGaskell saw this giant war of the dragons and saw it best to stay out of it, he preferred unicorns, unicorns didn't have massive wars and all they did was ride on rainbows all day.
Little did KPDGaskell know, by him just thinking about unicorns he had accidentally created them, though these unicorns were green, no one ever found out why, they just were.
And so these green unicorns began to roam the land, soon they realized that they drew power from the same magical grid as dragons* and decided that something had to be done...
*Both being mythological creatures created by Gods that can be only explained as either good humored or just plain silly.
"Note for Americans and other aliens: Milton Keynes is a new city approximately halfway between London and Birmingham. It was built to be modern, efficient, healthy, and, all in all, a pleasant place to live. Many Britons find this amusing." -Good Omens