Edi's database is quite handy, but for a database sorted by nation, you can check out
http://www.freewebs.com/dominions2/
When its up, that is. Its been pretty reliable until the past few days. I'm uncertain whether its up to date or not (but there is a version dedicated to dom3), but if you have trouble accessing it, I could upload a version off my harddisk this afternoon, maybe.