João de Trasto captained in 1415 the first exploratory expedition dispatched by Prince Henry the Navigator of Portugal. Probably departing from the port of Lagos, the Portuguese nobleman was forced by foul weather to part of the Grand Canary island called Telli. Returning to Portugal, he again encountered a fierce storm and only with great difficulty arrived in port.

Though the mission failed to reach any undiscovered territory, Henry persisted and ultimately succeeded in rediscovering numerous Atlantic islands and charting most of the western coast of Africa.

The story of Trasto is related by contemporary historian Diogo Gomez, himself a former explorer under Prince Henry. Gomez, generally reliable, committed several errors regarding the dates of early voyages; some modern scholars have suggested Henry's first expedition departed as early 1412, but there is no solid evidence for the assertions.

References

• Major, Richard Henry. The Life of Prince Henry of Portugal surnamed the Navigator and Its Results from Authentic Contemporary Documents. Ed. John Ralph Willis. Second Edition. London: Frank Cass & Co. Ltd., 1967. Pages 64-65.