Editing Alvise Cadamosto (section)

=== Achievement ===

The record of Portuguese discoveries prior to Alvise Cadamosto did not seem to have gone beyond the [[Sine-Saloum]] delta.<ref>See the review of expeditions by Teixeira da Mota (1946).</ref>  The furthest pre-Cadamosto seems to have been the singular expedition of [[Álvaro Fernandes]] in 1446, which may have reached as far as [[Cape Roxo]], but this was not followed up. The 1447 expedition led by [[Estêvão Afonso]] did not go beyond the beginning of the estuary of the Gambia River, and thereafter expeditions below [[Cape Vert]] were largely suspended by Prince Henry.  The principal barrier to the Portuguese seems to have been belligerence of the Niumi-Bato ([[Niominka]]) and the Niumi-Banta ([[Mandinka people|Mandinka]] of Niumi (Barra)), both led by the same king, Niumimansa.<ref>Teixeira da Mota (1946)</ref>  Cadamosto encountered that hostility on his first expedition of 1455.  But on his second trip, in 1456, opposition fell away for some reason, and he managed to become the first European (along with [[Antoniotto Usodimare]] and their anonymous companions) to sail up the Gambia River.  It is uncertain what caused this change of attitude from one year to the next – a new Niumimansa? A shift in senegambian politics?  The unreliable [[Diogo Gomes]] later boasted that he sailed to the Gambia sometime between 1456 and 1458 and single-handedly negotiated a peace with the Niumimansa, although this is likely exaggerated.<ref>Diogo Gomes, [https://books.google.com/books?id=-USdAAAAMAAJ&pg=PA282 p.282]; Russell, 2000 p.331.  However, Cortesão (1931: p.37) suggests it was Diogo Gomes is truthful, that Cadamosto never undertook his second trip at all, but pinched the account – including the dealings with Battimansa, Niumimansa etc. – wholesale from Gomes and others.  Curiously, Damião de Góis (1567:p.22) credits them with discovering the Cape Verde islands, but makes no mention of their second entry into the Gambia or sojourn there, claiming instead they sailed straight from the islands to Casamance, and went on as far only to Cape Roxo, before turning back.</ref>)

Once they opened the Gambia River, Cadamosto and Usodimare led the next great leap of Henrican discoveries in Africa – [[Cape Verde islands]], the [[Casamance River]], [[Cape Roxo]], [[Cacheu River]] and finally the [[Geba River]] and [[Bissagos Islands]].  The length of coast they discovered in 1456 was the greatest leap in the Portuguese era of discoveries since 1446. Much the same coast would be covered again by [[Diogo Gomes]] around 1458 (possibly as early as 1456, probably sent by Henry as a follow-up to Cadamosto's report) and 1462.  Cadamosto's furthest marker would only really be surpassed by [[Pedro de Sintra]] in 1461–62.