I made a new dynasty, conquered the Baltic in a Holy War and changed my culture to Latvian (Lettigallien or w/e its spelt) and my heir became Romuva (Pagan).

Insane bonuses, I get "Warrior Cult" (360 Heavy Infantry, 120 archers / light warriors) and also a "Warrior Gathering" (112 warriors and upgradable).  I can now call upon an army of 30,000 men but I think I need more before the Mongols come to Europe.