Aspilcueta, Juan (surnamed Navarro), a Spanish missionary, was born in the kingdom of Navarre. He was related to the family of Xavier and of Loyola, and entered the Order of Jesuits in 1544. He went to Brazil in company with Nobrega in .1549, and surpassed all the other missionaries in the art of subduing the Indians. He was the first to gain a correct use of their language and preach in their forests. He also made important discoveries in the geography of Brazil, and was placed at the head of an exploring party. This expedition is one of the most important of the 16th century. He died at Bahia in 1555. See Hoefer, Nouv. Biog. Generale, s.v.