Question: When did the Portuguese explore the Gold Coast of the area that the Bantu of East and Southern Africa migrated from?

full_context: Document 1: Spice trade: The first country to attempt to circumnavigate Africa was Portugal, which had, since the early 15th century, begun to explore northern Africa under Henry the Navigator. Emboldened by these early successes and eyeing a lucrative monopoly on a possible sea route to the Indies the Portuguese first crossed the Cape of Good Hope in 1488 on an expedition led by Bartolomeu Dias. Just nine years later in 1497 on the orders of Manuel I of Portugal, four vessels under the command of navigator Vasco da Gama rounded the Cape of Good Hope, continuing to the eastern coast of Africa to Malindi to sail across the Indian Ocean to Calicut, on the Malabar Coast. in south India -- the capital of the local Zamorin rulers. The wealth of the Indies was now open for the Europeans to explore; the Portuguese Empire was the earliest European seaborne empire to grow from the spice trade.
Document 2: European colonisation of Southeast Asia: The spice trade was made possible by the maritime trade route. In 1498, the Portuguese navigator, Vasco da Gama, sailed round the Cape of Good Hope and opened up a sea route from Europe to India. Bringing home samples of exotic oriental products, da Gama greatly increased European interest in the new trade route and the new trade route quickly facilitated the expansion of trade. Eventually, the Dutch wrestled control of it from the Portuguese in the 17th century, and in the 18th century, the British gained control of it from the Dutch. Nevertheless, the spice route greatly increased trading activities, deepened the economic relations between Europe and Southeast Asia and as a result, more European merchants found their way to Southeast Asia.
Document 3: Kenya: The African Great Lakes region, which Kenya is a part of, has been inhabited by humans since the Lower Paleolithic period. By the first millennium AD, the Bantu expansion had reached the area from West - Central Africa. The borders of the modern state consequently comprise the crossroads of the Niger - Congo, Nilo - Saharan and Afroasiatic areas of the continent, representing most major ethnolinguistic groups found in Africa. Bantu and Nilotic populations together constitute around 97% of the nation's residents. European and Arab presence in coastal Mombasa dates to the Early Modern period; European exploration of the interior began in the 19th century. The British Empire established the East Africa Protectorate in 1895, which starting in 1920 gave way to the Kenya Colony. Kenya obtained independence in December 1963, but remained a member of the Commonwealth of Nations. Following a referendum in August 2010 and adoption of a new constitution, Kenya is now divided into 47 semi-autonomous counties, governed by elected governors.
Document 4: European exploration of Africa: European exploration of Sub-Saharan Africa begins with the Age of Discovery in the 15th century, pioneered by Portugal under Henry the Navigator. The Cape of Good Hope was first reached by Bartolomeu Dias on 12 March 1488, opening the important sea route to India and the Far East, but European exploration of Africa itself remained very limited during the 16th and 17th centuries. The European powers were content to establish trading posts along the coast while they were actively exploring and colonizing the New World. Exploration of the interior of Africa was thus mostly left to the Arab slave traders, who in tandem with the Muslim conquest of the Sudan established far - reaching networks and supported the economy of a number of Sahelian kingdoms during the 15th to 18th centuries.
Document 5: Republic of the Congo: The region was dominated by Bantu-speaking tribes at least 3,000 years ago, who built trade links leading into the Congo River basin. Congo was formerly part of the French colony of Equatorial Africa. The Republic of the Congo was established on the 28th of November 1958 but gained independence from France in 1960. The sovereign state has had multi-party elections since 1992, although a democratically elected government was ousted in the 1997 Republic of the Congo Civil War, and President Denis Sassou Nguesso, who first came to power in 1979, has ruled for 35 of the past 40 years.
Document 6: Bantu expansion: The Bantu people originally came from West Africa, in the modern day Cameroon. The linguistic core of the Bantu family of languages, a branch of the Niger -- Congo language family, was located in the adjoining region of Cameroon and Nigeria. From this core, expansion began about 3,000 years ago, with one stream going into East Africa, and other streams going south along the African coast of Gabon, Democratic Republic of the Congo, and Angola, or inland along the many south - to - north flowing rivers of the Congo River system. The expansion eventually reached South Africa, probably as early as 300 AD.
Document 7: Republic of the Congo: Bantu-speaking peoples who founded tribes during the Bantu expansions largely displaced and absorbed the earliest inhabitants of the region, the Pygmy people, about 1500 BC. The Bakongo, a Bantu ethnic group that also occupied parts of present-day Angola, Gabon, and Democratic Republic of the Congo, formed the basis for ethnic affinities and rivalries among those countries. Several Bantu kingdoms—notably those of the Kongo, the Loango, and the Teke—built trade links leading into the Congo River basin.
Document 8: Middle Ages: In the early 15th century, the countries of the Iberian peninsula began to sponsor exploration beyond the boundaries of Europe. Prince Henry the Navigator of Portugal (d. 1460) sent expeditions that discovered the Canary Islands, the Azores, and Cape Verde during his lifetime. After his death, exploration continued; Bartolomeu Dias (d. 1500) went around the Cape of Good Hope in 1486 and Vasco da Gama (d. 1524) sailed around Africa to India in 1498. The combined Spanish monarchies of Castile and Aragon sponsored the voyage of exploration by Christopher Columbus (d. 1506) in 1492 that discovered the Americas. The English crown under Henry VII sponsored the voyage of John Cabot (d. 1498) in 1497, which landed on Cape Breton Island.
Document 9: Kingdom of Bamum: The Kingdom of Bamum (also spelled Bamoum, Bamun, Bamoun, or Mum) (1394–1884) was a pre-colonial Central African state in what is now northwest Cameroon. It was founded by the Mbum, a Bantu ethnic group from northeast Cameroon. Its capital was the ancient walled city of Fumban.
Document 10: Republic of the Congo: The Portuguese explorer Diogo Cão reached the mouth of the Congo in 1484. Commercial relationships quickly grew between the inland Bantu kingdoms and European merchants who traded various commodities, manufactured goods, and people captured from the hinterlands. After centuries as a major hub for transatlantic trade, direct European colonization of the Congo river delta began in the late 19th century, subsequently eroding the power of the Bantu societies in the region.
Document 11: History of the Cape Colony before 1806: The written history of the Cape Colony in what is now South Africa began when Portuguese navigator Bartolomeu Dias became the first modern European to round the Cape of Good Hope in 1488. In 1497, Vasco da Gama sailed along the whole coast of South Africa on his way to India, landed at St Helena Bay for 8 days, and made a detailed description of the area. The Portuguese, attracted by the riches of Asia, made no permanent settlement at the Cape Colony. However, the Dutch East India Company (VOC) settled the area as a location where vessels could restock water and provisions.
Document 12: Republic of the Congo: Ethnically and linguistically the population of the Republic of the Congo is diverse—Ethnologue recognises 62 spoken languages in the country—but can be grouped into three categories. The Kongo are the largest ethnic group and form roughly half of the population. The most significant subgroups of the Kongo are Laari in Brazzaville and Pool regions and Vili around Pointe-Noire and along the Atlantic coast. The second largest group are the Teke who live to the north of Brazzaville with 17% of the population. Boulangui (M’Boshi) live in the northwest and in Brazzaville and form 12% of the population. Pygmies make up 2% of Congo's population.
Document 13: Portugal: Portugal spearheaded European exploration of the world and the Age of Discovery. Prince Henry the Navigator, son of King João I, became the main sponsor and patron of this endeavour. During this period, Portugal explored the Atlantic Ocean, discovering several Atlantic archipelagos like the Azores, Madeira, and Cape Verde, explored the African coast, colonized selected areas of Africa, discovered an eastern route to India via the Cape of Good Hope, discovered Brazil, explored the Indian Ocean, established trading routes throughout most of southern Asia, and sent the first direct European maritime trade and diplomatic missions to China and Japan.
Document 14: Portuguese discovery of the sea route to India: One of the sailors, Bartolomeu Dias passed the southernmost point of Africa known as the Cape of Good Hope in 1488. He declared it possible to travel to India by going around Africa. The Portuguese were then able to make an immense profit by using their own ships to retrieve the spices.
Document 15: Portuguese discoveries: 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.
ground_truth: 15th century
sub_queries: where did the bantu of east and southern africa migrate from Answer: West Africa
when did the portuguese explore the gold coast of West Africa Answer: 15th century