Trpimir was a notable Croatian ruler from the 9th century, specifically known for being a duke of Croatia. He is often recognized for his efforts in consolidating power and promoting Christianity in the region. His reign is marked by the establishment of a more organized governance structure and the strengthening of ties with the Byzantine Empire. Trpimir is also remembered for the Trpimir's Charter, a significant document that outlines the rights and privileges granted to the church and nobility during his rule. This charter is an important historical source for understanding the political and social landscape of medieval Croatia.