Stefan the First-Crowned was the first king of Serbia, reigning from 1217 to 1228. He was a member of the Nemanjić dynasty and played a crucial role in establishing the Serbian state. His coronation marked the transition of Serbia from a principality to a kingdom, solidifying its independence and influence in the region. Stefan was known for his efforts to strengthen the church and promote Christianity in Serbia. He worked closely with the Byzantine Empire and sought to expand his territory through diplomacy and military campaigns. His reign laid the foundation for future Serbian rulers and the development of the nation.