Hiccup Haddock:

Prologue - the Story of Astrid Hofferson and the Heart of Draghasha:

In the beginning, there were only humans reigning the world but one day, a mysterious creature came from the heights of the sky, it was a dragon-god: Draghasha. Using the power of his magical heart, he created dragons of seven families to rule the world besides humans and for humans to befriend and love them and his body formed a magical island known as the Dragon Haven for all dragons to live there.

His heart held the greatest power of all, not just dominance of the world but dominance over dragons, it was what gave dragon's strength, power and their life.

But in time, some humans began to seek his heart, they thought that whoever possessed the heart would have power over dragons and having power over dragons meant power over the whole world.

But one day the most daring of them all flew across the Barbaric Sea to take it. She was a demigoddess of the earth and skies, she was a warrior, a trickster, a shapeshifter who could transform into any dragon with the power of her magic axe and her name was Astrid Hofferson.

But without his heart, Draghasha and his isle of Dragon Haven began to crumble giving birth to a terrible darkness and wicked dragon monsters. Astrid tried to escape but was confronted by another who sought the heart, The Red Death: Dragizer, a horrible dragon of fire and death. Astrid was struck from the sky never to be seen again and her magical axe and the heart of Draghasha were lost forever.

Because of the theft of the heart, dragons grew to hate humans believing it was they who sent Astrid to take it and were responsible for the death of their creator and home, wars were fought, lives were lost and for over a thousand years, the war between dragons and humans never ended.