The history of the Kingdom of Portugal from the Illustrious Generation of the early 15th century to the fall of the House of Aviz in the late 16th century has been named the "Portuguese golden age" and the "Portuguese Renaissance". During this period, Portugal was the first European power to begin building a colonial empire as during the Age of Exploration Portuguese sailors and explorers discovered an eastern route to India as well as several Atlantic archipelagos and colonized the African coast and Brazil. They also explored the Indian Ocean and established trading routes throughout most of southern Asia, sending the first direct European maritime trade and diplomatic missions to Ming China and to Japan, at the same time installing trading posts and the most important colony: Portuguese Macau. The Portuguese Renaissance produced a plethora of poets, historians, critics, theologians, and moralists. The Cancioneiro Geral by Garcia de Resende is taken to mark the transition from Old Portuguese to the modern Portuguese language.

The Kingdom of Portugal was a monarchy in the western Iberian Peninsula and the predecessor of the modern Portuguese Republic. Existing to various extents between 1139 and 1910, it was also known as the Kingdom of Portugal and the Algarves after 1415, and as the United Kingdom of Portugal, Brazil and the Algarves between 1815 and 1822. The name is also often applied to the Portuguese Empire, the realm's overseas colonies.