Thirteenth century could be the perfect time for invading politically divided Europe. One of the main powers of the continent which were Holy Roman Empire, Papacy, Hungarian Kingdom and Poland had strong conflicts among each other. During the Mongol Invasion, there were power struggle between Holy Roman Emperor Frederick II. and the Papacy in Europe. To Central Eastern Europe, Hungarian Kingdom and Poland had internal struggles. Also, Poland divided to four principality, Hungarian Kingdom had ec ...