Based on the Treaty of Tordesillas, the Portuguese Crown, under the kings Manuel I, John III and Sebastian, also claimed territorial rights in North America(reached by John Cabot in 1497 and 1498). To that end, in 1499 and 1500, João Fernandes Lavrador explored Greenland and the north Atlantic coast of Canada, which accounts for the appearance of “Labrador” on topographical maps of the period. Subsequently, in 1500-1501 and 1502, the brothers Gaspar and Miguel Corte-Real explored what is today the Canadian province of Newfoundland and Labrador, and Greenland, claiming these lands for Portugal. In 1506, King Manuel I created taxes for the cod fisheries in Newfoundland waters. Around 1521, João Álvares Fagundes was granted donotary rights to the inner islands of the Gulf of St. Lawrence and also created a settlement on Cape Breton Island to serve as a base for cod fishing. Pressure from natives and competing European fisheries prevented a permanent establishment and was abandoned five years later. Several attempts to establish settlements in Newfoundland over the next half-century also failed.