During Frederick's long stays in Italy, the German princes became stronger and began a successful colonization of Slavic lands. Offers of reduced taxes and manorial duties enticed many Germans to settle in the east in the course of the Ostsiedlung. In 1163 Frederick waged a successful campaign against the Kingdom of Poland in order to re-install the Silesian dukes of the Piast dynasty. With the German colonization, the Empire increased in size and came to include the Duchy of Pomerania. A quickening economic life in Germany increased the number of towns and Imperial cities, and gave them greater importance. It was also during this period that castles and courts replaced monasteries as centers of culture. Growing out of this courtly culture, Middle High German literature reached its peak in lyrical love poetry, the Minnesang, and in narrative epic poems such as Tristan, Parzival, and the Nibelungenlied.
During Frederick's long stays in Italy, the German princes became stronger and began a successful colonization of Slavic lands. Offers of reduced taxes and manorial duties enticed many Germans to settle in the east in the course of the Ostsiedlung. In 1163 Frederick waged a successful campaign against the Kingdom of Poland in order to re-install the Silesian dukes of the Piast dynasty. With the German colonization, the Empire increased in size and came to include the Duchy of Pomerania. A quickening economic life in Germany increased the number of towns and Imperial cities, and gave them greater importance. It was also during this period that castles and courts replaced monasteries as centers of culture. Growing out of this courtly culture, Middle High German literature reached its peak in lyrical love poetry, the Minnesang, and in narrative epic poems such as Tristan, Parzival, and the Nibelungenlied.