Choosing a military career as a young man, he participated in the wars of France and the Netherlands, under the leadership of Prince Emmanuel Philibert, Duke of Savoy, and Lamoral, Count of Egmont, and directly with Rodrigo de Basan.
He was amongst the victors of the Battle of Gravelines (1558) over the French armies of Marshal Paul de Thermes.
From there he went to Quito, Ecuador, where he began to write the Miscelánea Antártica, finishing it in 1586 at Lima where he resided from 1596 to 1604.
[2] In the years 1602–1603, he wrote a letter giving valuable details concerning the regions of Pelechuco and Apolobamba in eastern Bolivia, between the Andes and the Beni River.
It contains alleged Amerindian traditional records of the coming to South America of white men who are said to have preached the gospels to the aborigines; also a theory that the Indians of Patagonia and Chile are the descendants of pirates of Macassar.