15/1600, but for the rest your assumptions are correct.
Allthough Mendicant sent out a message declaring war just before the landing, he did not officially declare war game mechanics wise.
I see. I guess that's the way to avoid the squeezed peasants to have some wish of independence for a real war declaration. I am curious to know how much is "just before". The turn before? Enough time to allow the Fissoan nobles fighting in Falkirk to return and defend their lands?
