King João II (1455 - 1495)
The son of Afonso V, João II was crowned king in 1481. His father had involved him in the strategy for the expansion of the Portuguese realm since 1474, which he came to manage with great vision, despite the fact that he had not yet reached the age of 20.
The principle of mare clausum, which established that dominion over the seas depended on who discovered them, was the basis for the Treaty of Alcácovas-Toledo (1480), in which João agreed to divide the colonial territories in the Atlantic, with Spain keeping the Canary Islands and Portugal free to explore the route along the coast of Africa.
During his reign the whole western coast of Africa was sailed, reaching the Cape of Good Hope. On land, the travels of Pêro da Covilhã and Afonso de Paiva, paved the way for the discovery of the sea route to India by Vasco da Gama (1498).
In 1494 the Treaty of Tordesillas "divided" the world into two zones of influence - a Portuguese zone and a Spanish zone. In the Portuguese zone Brazil was discovered, which has fuelled speculation amongst historians that João II may have had knowledge that the land existed before he signed the treaty.
In terms of internal affairs, João's actions focused on consolidating royal power. He harshly repressed conspiracies amongst the nobility and suppressed the power of the leading families in the realm. Between 1481 and 1485 a number of noblemen were either killed or imprisoned, amongst them the Duke of Viseu. The death of the latter made it possible for Manuel I, João's brother-in-law, to ascend to the throne after the premature death of João son, the Crown Prince Afonso.
João II died in the Algarve in 1495. He was initially laid to rest in Silves Cathedral. In 1499 his remains were transferred to the Monastery of Batalha.