Inspired by the Pope's call for a Holy War, Scandinavian rulers and German military monks conquered and settled Finland, Estonia and Prussia, before turning on the eastern empires of Orthodox Novgorod and pagan Lithuania. These 'Northern Crusades' are less celebrated than those in the Middle East, but they were also far more successful. Vast new territories became and remain Christian, while the central institutions of medieval Western Europe - churches, castles, manors, guilds, parliaments and feudal law codes - were introduced into a dark and inhospitable outer world. Now newly revised in the light of the recent developments in Baltic and Northern medieval research, this overview provides a balanced and compelling account of a tumultuous era.