How long does peace agreement lasts?

[Flammehav]

I attacked some muslim weak power, but before I coudl do much about I got attacked by a much stronger christian power and made hastily peace with the muslims so I coudl focus on beating back the invaders.

Now it's been almost 10 years and apperantly I still got a peace agreement with the muslims. How long does peaceagreement last in CK and what happens if I break them?

 

[unmerged(183166)]

Until your ruler dies and you lose 100 prestige, a small penalty.

 

[TempestDK]

It lasts until either ruler who signed the peace deal dies