How many seasons/years do we have to make King?

[Hystorm]

Before the game ends or something stating we lost?
If spoiler, please reply protected.

[Lucandriel]

Took me 3 seasons to became a king and as far as I know you can always go back to the beginning of the season, but am not sure. I don't remember reading on the forums or anywhere that there is a time limit on the game.