The name Prussia comes from the Borussi or Prussi people who lived in the Baltic region and spoke the Old Prussian language. Ducal Prussia was a fiefdom of the Kingdom of Poland until 1660, and Royal Prussia was part of Poland until 1772. In the late eighteenth and early nineteenth centuries, most German-speaking Prussians started thinking of themselves as part of the German nation. They thought the Prussian way of life was very important: 