Diego García de Moguer

He ordered Captain Caro to abandon the place as he, García, alone had been charged by Spain to explore the region.

[6] García continued upstream between what are now the towns of Goya and Bella Vista where he met Cabot who forced him to cooperate in trying to find the legendary Sierra de la Plata.

Garcia and Cabot continued their attempts to explore the mythical kingdom about which they had heard from Captain Francisco Cesar, hearing that the place was rich in gold, silver, and sheep (llamas) with which fabrics were made.

[2] Arguments between García and Cabot eventually ended both expeditions, the two men returning to Spain to settle their disputes through legal measures.

The reason was that Cabot who was assigned to go to the Spice Islands never went there but explored the Sierra de la Plata which was a violation.

[11] He passed the Cape Verde island of Santiago, then continued to Brazil and on to the estuary of the Uruguay and Paraná rivers.