Some Early Contributions to the History of Geomagnetism—VII

Abstract

Joäo de Castro was a Portuguese naval commander and explorer, born in Lisbon in 1500, the son of Alvaro de Castro, governor of that city. As a young man he distinguished himself in the campaigns against the Moors in North Africa. In 1545 he was sent to the “Indies” with six ships where he overthrew Mahmud, King of Gujarat, relieved the besieged town of Diu, and achieved a number of other military successes.1 In 1547 he was appointed Viceroy of India by Joäo III, but soon after receiving his full commission he died at Ormuz, June 6, 1548.2