Game of Thrones : seasons 1-2-3 explained in less than 5 minutes

(This video is translated from the original french version available on Le Monde.fr)

For more than a year, the Seven Kingdoms of Westeros have been facing an unprecedented political crisis : the major clans are fighting, and the threat of invasion is looming from both North and East.

But how exactly did  things come this far ?

Here are the answers, condensed in less than 5 minutes.