João de Castro

Portuguese naval officer
verifiedCite
While every effort has been made to follow citation style rules, there may be some discrepancies. Please refer to the appropriate style manual or other sources if you have any questions.
Select Citation Style
Share
Share to social media
URL
https://mainten.top/biography/Joao-de-Castro
Feedback
Corrections? Updates? Omissions? Let us know if you have suggestions to improve this article (requires login).
Thank you for your feedback

Our editors will review what you’ve submitted and determine whether to revise the article.

External Websites
Quick Facts
Born:
Feb. 7, 1500, Lisbon, Port.
Died:
June 6, 1548, Goa, Portuguese India (aged 48)

João de Castro (born Feb. 7, 1500, Lisbon, Port.—died June 6, 1548, Goa, Portuguese India) was a naval officer who helped preserve the Portuguese commercial settlement in India and contributed to the science of navigation with three roteiros (pilot books). He was also the first to note the deviation of the ship’s compass needle created by the magnetic effect of iron objects.

The son of Alvaro de Castro, governor of Lisbon, and a student of the celebrated Portuguese mathematician and geographer Pedro Nunes, he spent 20 years in North Africa before sailing to western India in 1538. There he helped to end the Ottoman-Indian siege of the Portuguese fort at Diu. He sailed up the Red Sea to Suez (1540–41) and returned to Portugal in 1543. In 1545 he commanded the Portuguese fleet that helped end another siege of Diu. He served as viceroy of Portuguese India for only a few months before his death in the arms of the missionary St. Francis Xavier. Castro’s pilot books, remarkable for their scientific observations, were published in Paris, France (1833), and in Oporto (1843) and Lisbon, Port. (1882).

This article was most recently revised and updated by Encyclopaedia Britannica.