They did not so much mind sharing it, along the line agreed upon in the Treaty of Tordesillas, with the Portuguese, but the ingress of the English and French infuriated them.
The Basque people of the north-east corner of Spain were a hardy seafaring folk, especially bold in the pursuit of whales in the Bay of Biscay, and eager to take a share in the salt-fish trade.

This desire took them in the fourteenth and fifteenth centuries to Ireland and Iceland.

They began to fish off the Newfoundland coasts perhaps as early as 1525.

About this time also the Emperor Charles V, King of Spain, having through one great Portuguese sea captain--Magalhaes (Magellan)--discovered the passage from Atlantic to Pacific across the extremity of South America, thought by employing another Portuguese--Estevao Gomez--to find a similar sea route through North America, which would prove a short cut from Europe to China.

This was the famous "North-west Passage" the search for which drew so many great and brave adventurers into the Arctic sea of America between 1500 and 1853, to be revealed at last by our fellow countrymen, but to prove useless to navigation on account of the enormous accumulation of ice.
[Footnote 12: Corte-Real's name of Terra Verde ("Greenland") was soon dropped in favour of the older English name "New Land" (Newfoundland, Terra Nova).