I started playing this way after seizing control of the world through loads of battles. I kinda got sick of fighting in that game so I started a new one as Portugal and played the game peacefully. The way I did this was by quickly selling Pamplona and my allegiance to the Spanish and my allegiance to the Moors for a fairly decent sum of money. After allying with my neighbours I started calmly building up Lisbon and making it huge and grand. I dispanded lots of troops so that I didn't have to pay 'em and after twenty turns or so I was packing a mighty Economy. After raising 300000 florins from Lisbon, I bought the fortress of Granada from the Moors for 100000 florins and converted it into a Citadel. I had Perfect relations with every faction and a 'Very Reliable' rep. When the time came I made use of my mighty economy and invaded the Americas using some elite troops. I then set about setting some merchants on Brazil and Mexico's rich resources. I would recommend this way of playing to anyone who's tired of doing loads of fighting. I found it surprisingly fun to play this way- you can build huge metropolis' in peace. Another cool thing about this is watching the rest of the world fight around you- great fun indeed!