Antonio de Portugal (Lisbon, 9 September 1516-1516), was the tenth and last son of the marriage between Manuel I of Portugal and Maria de Aragón, his second wife, being thus grandson by paternal way of Ferdinand of Portugal, Duke of Viseu and of the Infanta Beatriz, and by maternal route, of the Catholic Monarchs, Isabel of Castile and Ferdinand of Aragon.
He died shortly after being born on an indeterminate date. Although not immediately fatal, the consequences of the tenth pregnancy of Queen Mary (already at risk, due to her thirty-four years of age) caused her death on March 7 of the following year, which led King Manuel to his third marriage this time with Leonor of Austria.
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