(Bon je suis un peu en retard je sais pas si tu joues toujours)
Voici ce que j'ai trouvé sur un site en anglais :
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How are you suppose to beat this mission? I know you are suppose to capture the other king, but where is he?
At first he's in the northwest, but if you wait he will come to your priest (father Luque). Then he will turn on you and his troops (in blue) will attack. At this point, all you have to do to complete the mission is surround him with your own troops. Only problem is, you have go through about a million of his troops first. Good news is, they're neither skilled nor brave. Use your conquistadores and hallebardiers to wipe them out. I also recommend capturing buildings, as they're empty and pretty lethal once your men are inside. Go for the fortresses, which act as a rallying point for the routed ennemy troops. You should be able to eliminate enough of them so that all you have to do is locate the king and surround him (you won't be able to kill him).
In my game he ended up near the mill to northwest of the main plaza, but maybe his mouvements are random depending on what you do.
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