Just thought I'd let people know about a new game called Crusader Kings. It is a strategy game set in medieval Europe in the years 1066-1453. It has rulers, dynasties, feudal fiefs, armies, provinces, all that stuff we have and love in Birthright. I've been playing it for several weeks now and can only recommend it to any BR player. Here's a link to the game's website:

http://www.paradoxplaza.com/crusaderkings.asp