On my first campaign I played the English on H/H. First thing I did was marry my heir to the French princess so I could wipe out the Scots and Flemish with out interference.

When I finished my conquests I was logically planning out my attack on France. Only problem was that I had to do everything one turn or face excommunication by the pope. Then it struck me since I was loaded with cash I might save myself some trouble and buy out some of their Castles.

I got Angers for 1000 tribute over 2 turns, Bordeaux 1500 tribute over 5 turns and Toulouse 2400 tribute over 10 turns. Note I had a very good reputation and relationship with France plus marriage alliance. Afterwards I realised I paid too much for Toulouse so cancelled my tributes to France. They still remained allies for some stupid reason as my army was already outside Paris.

Killed their King and captured Paris but the stupid Pope wouldn't let me finish them off. So I parked my army outside Dijon where most of their army was and waited.

Finally they attacked with two full stacks, great battle as they had decent calvary and dismounted knights while I had only Billmen and LongBowmen so it was close. In the end I wiped them out but lost half my army.

Afterwards they wanted a ceasefire so why not. Then to see how much they wanted peace I tried to buy Mertz for 5000 and Bern for 4000 both were sold to me, I guess France was broke. Next turn when the threat of excommunication was finished and with my Pope in Rome I captured Dijon and Rheims.

Did I get lucky or is it suppose to work like this? Because I found it a very easy and cheap way to take Castles, you can cancel tributes so it doesn't cost you anything and you already have units there at the castle to garrison it. It seems to work with Castles more then Cities though(I bought all their Castles), France has a lot of Castles to begin with, around five compared to two the English have.