Bartolomeu Dias was the first European explorer of the South African coast. Nothing is known about his early life, but in December 1481 he was in command of one of the ships in an expedition to the coast of Guinea, led by Diogo de Azambuja. In 1486 he was an officer in the household of the Portuguese King Joao II, in Lisbon, with resposibilities somewhat like those of a present day customs officer. In October that year the King appointed him in charge of an expedition to continue the exploration of the African west coast, following the earlier expedition of Diogo Cao*, which reached as far south as present Cape Cross on the Namibian coast. Dias left Portugal in August 1487 in command of three ships, two caravels of about 50 tons and a small store ship. The pilot of the flagship was Pedro de Alenquer, who later sailed to India with Vasco da Gama*. The store ship was commanded by Bartolomeu's brother, Diogo Dias, who also later accompanied da Gama and travelled to India several times. No contemporary description of the expedition's journey seems to have survived. The available information about it derives mainly from sources describing da Gama's later voyage, some early maps of Africa, and the writings of the historian Barros more than 60 years after the event.
Dias probably sailed directly across the Gulf of Guinea and then proceeded southwards along the coast. He reached Namibia in December 1487, entering present Walvis Bay on the 8th of that month. Here the expedition remained for a week or two. They touched land at Spencer Bay on the 21st, and anchored in Luderitz Bay around Christmas. They probably left their supply ship either in Luderitz Bay or in a bay along the coast of southern Angola. Proceeding further they named various coastal features down to present Lambert's Bay, which was reached around 6 January 1488, but did not land again. It seems as if contrary winds led Dias to decide to sail westwards into the Atlantic Ocean, before turning back towards the coast. This manoeuvre gave rise to the subsequent navigational practice of sweeping far out to sea and then running along a line of constant latitude to round the Cape. However, Dias's ships were driven far south of Cape Point by the wind. Turning northwards, the expedition reached the southern Cape coast at the beginning of February, where they saw people tending large herds of cattle. They landed at present Mossel Bay, where they came in conflict with some of the Khoi inhabitants. Another landing was made, probably in Algoa Bay. At this time a majority decision was reached to turn back, though Dias persuaded his crews to continue eastwards for two or three days more. Early in March the expedition turned back, probably at the mouth of either the Keiskamma River or the Great Fish River. On 12 March 1488 they planted a limestone cross at Kwaaihoek, a few kilometers west of the mouth of the Bushman's River, where its remnants were found in 1938 by Eric Axelson. The return voyage proceeded slowly. On 23 April the ships took in water, apparently at Struys Bay, while Cape Agulhas was reached only on 16 May. Towards the end of May they reached False Bay. Another cross was erected on the Cape peninsula around 6 June, and Dias is believed to have named Cape Point the Cabo de boa Esperanca, or "Cape of Good Hope". The expedition did not visit either Table Bay, Saldanha Bay, or St Helena Bay, and took an extraordinary six weeks to reach Luderitz Bay by about 24 July. Dias erected his third and last cross on the point to the west of the bay. Fragments were recovered in 1855 and 1953. The expedition called at the island of Principe, where they found the seafarer Duarte Pacheco Pereira*, who had been sent out to survey the Guinea coast but had lost his ship. Seventeen years later Pacheco Pereira included some information about Dias's voyage in his book Esmeraldo de Situ Orbis, a manual for navigators of the African and Asian coasts.
Dias reached Spain during the first half of December 1488. He reported his discoveries, including some 2000 km of the southern African coast never visited by Europeans before, to the king, but seems to have received no reward and little recognition. A year after his return a map of the known world was compiled in Italy by Henricus Martellus, based on Portuguese information. This so-called Martellus map clearly shows some names given by Dias to features along the South African coast, though the east coast of Africa beyond Dias's furthest point is left blank. Dias also discovered the trade-wind system of the South Atlantic, and the best course across it to round the continent. This information was available to Vasco da Gama in 1497.
From 1488 Dias was employed in the gold trade of Guinea, still in command of his flagship. He then superintended the building and outfit of the vessels intended for Vasco da Gama's expedition. Twelve years after his epic voyage, in March 1500, he departed with a trading expedition to the East, consisting of thirteen ships commanded by Pedro Alvares Cabral. The fleet discovered the coast of Brazil, but then four of the ships, including that commanded by Dias, were lost in a storm in the South Atlantic. The marine mollusc Drillia diasi was named in Dias's honour, but the name is no longer in use.