King Peter I of Yugoslavia was born on June 11, 1844, and became the first king of the Kingdom of Serbs, Croats, and Slovenes in 1918, which was later renamed Yugoslavia. He was a member of the House of Karađorđević and played a significant role in uniting the South Slavic peoples after World War I. His reign was marked by efforts to establish a democratic government and promote national unity. During his rule, King Peter I faced numerous challenges, including political instability and ethnic tensions within the diverse kingdom. He was known for his commitment to democracy and social reforms. After a coup in 1929, he was forced to abdicate in favor of his son, King Alexander I, and spent his remaining years in exile, passing away on August 16, 1921.