I have got another story. I played Danes at that time. I found that Constantinople had changed hand several times due to the crusades. At one point, it was France, one of my allies, that occupied the city but with really weak army. So, I sent in the emissaries and waited for the revolt. It did happen the France troops retreated to the castle. I checked that it was one about one year to fall. Then just bought the province from the rebels. It worked. But unfortunately, the France army inside the castle got out for a last ditch defense. Instead of finding the rebel, it saw my newly recruited (or converted) army. So, the France king sent me the letter of gratitude (for saving his province). He also kindly attached the bill of ransom for my ,unfortunate to be there, ex-rebel army too. Well, It seems to me that I did nothing but buying that junk army twice.