1991 AD., Portugal, period of Portuguese westward discoveries commemorative, Lisbon mint, 200 Escudos, KM 659.

Portugal, period of Portuguese westward discoveries commemorative, engraver: D'Eca, Lisbon mint, 1991 AD.,
200 Escudos (ø 36 mm / 20,88 g), copper-nickel, 21,00 g. theor. mint weight, mintage 1.500.000 , axes coin alignment ↑↓ (180°), reeded edge,
Obv.: REPUBLICA / PORTUGUESA / 200 / ESCUDOS / 1991 / INCM - D'EÇA , coat of arms of Portugal on Toscanelli's map of 1474 inside and hexagon (Europe and Africa to the right, Asia and Japan ("Cipangu") left, Equatorial line); below, value and date, mint mark and engraver´s name flanking.
Rev.: NAVEGAÇÕES PARA OCIDENTE / 1452 1486 , Toscanelli's map in background, a stylized boat sailing left with 3 sailors on board holding the rudder, a map, an astrolabe and a sword with the cross of the Order of Christ, legend above, dates of this period of westward explorations below.
KM 659 .

Year / Mint Mark / Mintage
1991 / INCM / 1.500.000

Portuguese discoveries (Portuguese: Descobrimentos portugueses) are the numerous territories and maritime routes discovered by the Portuguese as a result of their intensive maritime exploration during the 15th and 16th centuries. Portuguese sailors were at the vanguard of European overseas exploration, discovering and mapping the coasts of Africa, Canada, Asia and Brazil, in what became known as the Age of Discovery. Methodical expeditions started in 1419 along West Africa's coast under the sponsorship of prince Henry the Navigator, with Bartolomeu Dias reaching the Cape of Good Hope and entering the Indian Ocean in 1488. Ten years later, in 1498, Vasco da Gama led the first fleet around Africa to India, arriving in Calicut and starting a maritime route from Portugal to India. Portuguese explorations then proceeded to southeast Asia, where they reached Japan in 1542, forty-four years after their first arrival in India. In 1500, the Portuguese nobleman Pedro Álvares Cabral became the first European to discover Brazil.

In 1453 the fall of Constantinople to the hands of the Ottomans was a blow to Christendom and the established business relations linking with the east. In 1455 Pope Nicholas V issued the bull Romanus Pontifex reinforcing the previous Dum Diversas (1452), granting all lands and seas discovered beyond Cape Bojador to King Afonso V of Portugal and his successors, as well as trade and conquest against Muslims and pagans, initiating a mare clausum policy in the Atlantic. The king, who had been inquiring of Genoese experts about a seaway to India, commissioned the Fra Mauro world map, which arrived in Lisbon in 1459. Dum Diversas (English: Until different) is a papal bull issued on 18 June 1452 by Pope Nicholas V. It authorized Afonso V of Portugal to conquer Saracens and pagans and consign them to "perpetual servitude". Pope Calixtus III reiterated the bull in 1456 with Inter Caetera (not to be confused with Alexander VI's), renewed by Pope Sixtus IV in 1481 and Pope Leo X in 1514 with Precelse denotionis. The concept of the consignment of exclusive spheres of influence to certain nation states was extended to the Americas in 1493 by Pope Alexander VI with Inter caetera.

In 1456 Diogo Gomes reached the Cape Verde archipelago. In the next decade several captains at the service of Prince Henry – including the Genoese Antonio da Noli and Venetian Alvise Cadamosto – discovered the remaining islands which were occupied during the 15th century. The Gulf of Guinea would be reached in the 1460s. In 1460 Pedro de Sintra reached Sierra Leone. Prince Henry died in November that year after which, given the meager revenues, exploration was granted to Lisbon merchant Fernão Gomes in 1469, who in exchange for the monopoly of trade in the Gulf of Guinea had to explore 100 miles (161 kilometres) each year for five years.[55] With his sponsorship, explorers João de Santarém, Pedro Escobar, Lopo Gonçalves, Fernão do Pó, and Pedro de Sintra made it even beyond those goals. They reached the Southern Hemisphere and the islands of the Gulf of Guinea, including São Tomé and Príncipe and Elmina on the Gold Coast in 1471. (In the Southern Hemisphere, they used the Southern Cross as the reference for celestial navigation.) There, in what came to be called the "Gold Coast" in what is today Ghana, a thriving alluvial gold trade was found among the natives and Arab and Berber traders.

In 1478 (during the War of the Castilian Succession), near the coast at Elmina was fought a large battle between a Castilian armada of 35 caravels and a Portuguese fleet for hegemony of the Guinea trade (gold, slaves, ivory and melegueta pepper). The war ended with a Portuguese naval victory followed by the official recognition by the Catholic Monarchs of Portuguese sovereignty over most of the disputed West African territories embodied in the Treaty of Alcáçovas, 1479. (See entry on Elmina.) This was the first colonial war among European powers.

In 1481 the recently crowned João II decided to build São Jorge da Mina factory. In 1482 the Congo River was explored by Diogo Cão,[56] who in 1486 continued to Cape Cross (modern Namibia).

more on https://en.wikipedia.org/wiki/Portuguese_discoveries , https://en.wikipedia.org/wiki/Dum_Diversas