In the 20th century, several monarchs played significant roles in their countries and the world. Notable figures included King George VI of the United Kingdom, who led during World War II, and King Faisal of Saudi Arabia, known for modernizing his nation and promoting oil production. These kings often faced challenges such as political upheaval and changing social dynamics. Many 20th-century kings also navigated the decline of traditional monarchies. King Juan Carlos I of Spain helped transition the country to democracy after the dictatorship of Franco. Meanwhile, King Bhumibol Adulyadej of Thailand was revered for his long reign and efforts in rural development, showcasing the evolving role of monarchy in modern governance.