Iberia and the vast western ocean

Armando Cortesão credits a 1424 map of the Atlantic, as being a map of the Americas. As usual I popped off a comment and am doing the research later.

Best I can garner, the Catholic states in mediaeval Atlantic Iberia ("Spain" did not exist) including, but not exclusively, the Portugal rump frequently bumped into Atlantic islands. Before the Catholics, the Almoravid court to their south (which still owned Lisbon, until Afonso I 1147) sent thither one Ahmad Ibn 'Umar, "Raqsh al-Auzz". Of these lands the Canaries were known to the Romans but lost to the West over the Dark Ages. Other islands flitted in and out of legend; Islamic Lisbon for her part (probably after Raqsh) had (re?)discovered the "Sargasso Sea". The "Seven Cities" was a consistent myth in these days - that there existed a western civilisation, southwest of the Sargasso. And that is where the Cities remained: in fantasyland.

Prince Henry is the man whom the Portuguese credit with bringing some order to these legends, nailing down the exact positions of the Azores and Madeira. The Flores island, slightly further west, slightly later. But as noted the sailors had long suspected that such lands were out there, before Henry; and they insisted that not all the lands were accounted for, after Henry.

Over the AD 1470s festered that dispute over the Castilian Succession, breaking out into open war 1475. At stake here was whether there was even going to be a "Portugal" or a "Spain", and what their shape should be. The war ended with a coastal Portugal facing west; and a Spain facing north, southwest, Mediterranean, and European. Portugal also ended up with Madeira and the Azores, giving them a head start at the Volta do Mar.

That the Portuguese remained adamant that, yes, the Seven Cities / Antilles were still out there, hints (to me) that some west-Iberian sailor(s) had found some Neolithic establishment on the South American coast. Perhaps on the Orinoco. Likely not Amazon though. One does wonder about the Postclassic Maya...

The more-publicised Portuguese trips west of the Azores didn't go all that great. The Dulmo[=Ferdinand d'Ulm]-Estreito 1487 expedition was infamous here. The West Africa navigations were going better so, that's what Portugal's royals concentrated on. The Portugal 1487 failure is telling me that Portugal 1492 had lost confidence in her own maps. (AFTERTHOUGHT 8/25: did nautical guilds keep maps which they withheld from the King...?)

This is a long way toward saying that although we can allow for (very!) sporadic Iberian hits on the Venezuela / Brasil coast... I should not call them Portuguese. Portugal qua Portugal is a fifteenth-century construction that failed to follow up on the old Iberian probes and failed to extend Henry's discoveries. Until after 1492.