Peter I of Serbia was born on June 29, 1844, and became the King of Serbia in 1903. He was a member of the House of Karađorđević and played a significant role in modernizing Serbia. His reign saw the establishment of a constitutional monarchy and significant social and economic reforms. During his rule, Peter I led Serbia through the Balkan Wars and World War I, strengthening national identity and unity. He was known for his dedication to the Serbian people and his efforts to improve their living conditions. Peter I passed away on August 16, 1921, leaving a lasting legacy in Serbian history.