All of the historical sequences in the movie have been shot and will be heard in Spanish.  Makes sense, right? It’s only logical to have people people speaking Spanish if most of the movie takes place in Spain. Hopefully it will make the film more believable, even though it is still set in a slightly alternate fantasy world. And it shows that the filmmakers embraced a bit of authenticity to really enhance the film’s setting and tone. 

While this decision brings realism to the film, let’s hope that the actors don’t have the unusual foreign accents, like what we heard from the guards in Assassin’s Creed II or Unity.