"Reis de Portugal" refers to the kings of Portugal, a nation in southwestern Europe. The monarchy in Portugal began in the 12th century with Afonso I, who became the first king after the country gained independence from Leon. Over the centuries, the Portuguese monarchy saw various dynasties, including the Aviz and Braganza families, which played significant roles in the country's history. The reign of the kings of Portugal was marked by exploration, trade, and cultural development, particularly during the Age of Discoveries. This period saw the expansion of the Portuguese Empire, with notable figures like Vasco da Gama and Prince Henry the Navigator. The monarchy officially ended in 1910 when Portugal became a republic.