Joao II (Civ4)/Civilopedia

King Joao II of Portugal was a statesman that supported the exploration and exploitation of the undiscovered world. Arguably the first nation to discover America, under Joao's reign Portugal made several other important discoveries while also advancing the field of nautical navigation.
"I am the lord of lords, not the server of servants." These words, originally a castigation of rebellious nobles by Joao, would come to define the Portuguese king's reign. Joao's dislike of court intrigue and the inability for political opinion to influence his decisions made him an unpopular king amongst his peers. The King's early rule was defined by his efforts to curtail, and eventually crush, all internal corruption and opposition to his rule. After having intercepted conspiratorial letters between the Duke of Braganza and Queen Isabella I of Castile in 1483, Joao had the Duke executed, his family banished from Portugal, and his lands and wealth confiscated.
Joao II's policies focused primarily on the exploration and exploitation of maritime trade routes, particularly with India. The full extent of Portugal's explorations and discoveries remain largely unknown due to the government's secrecy, born of a fierce competition with its neighbor Castile. It is, however, argued that Portugal had already reached North America and Brazil by 1470 and 1480, respectively. This places their discovery of North America in advance of Christopher Columbus's voyage.
Portugal, under the reign of Joao, was also credited with the 1484 discovery of the Congo River, the 1488 rounding of the Cape of Good Hope (Africa's southern tip), and the 1493 settlement of the São Tomé and Príncipe Islands.
Disputes over rights of exploration between Castile and Aragon and Portugal would eventually lead to the Treaty of Tordesillas (1494) which split the world in half. Portugal would be responsible for exploring the Eastern hemisphere while Aragon and Castile would have the Western hemisphere.
Towards the end of his reign, Joao's only legitimate heir, Alfonso, died under mysterious circumstances. This prevented Portugal from inheriting ownership of Castile and Aragon through Alfonso's marriage to Isabella of Aragon - Isabella I of Castile and Ferdinand II of Aragon's eldest daughter. Joao II died without male heir in 1495, possibly poisoned by the vengeful Portuguese nobility and was succeeded by his first cousin, Manuel I.