Juan Fernández was a Spanish Jesuit lay brother

Lay brother

In the most common usage, lay brothers are those members of Catholic religious orders, particularly of monastic orders, occupied primarily with manual labour and with the secular affairs of a monastery or friary, in contrast to the choir monks of the same monastery who are devoted mainly to the...

 and missionary. He was the first European to a grammar and lexicon of the Japanese language

Japanese language

is a language spoken by over 130 million people in Japan and in Japanese emigrant communities. It is a member of the Japonic language family, which has a number of proposed relationships with other languages, none of which has gained wide acceptance among historical linguists .Japanese is an...

.

Life

In a letter from Malacca, dated 20 June 1549, Francis Xavier

Francis Xavier

Francis Xavier, born Francisco de Jasso y Azpilicueta was a pioneering Roman Catholic missionary born in the Kingdom of Navarre and co-founder of the Society of Jesus. He was a student of Saint Ignatius of Loyola and one of the first seven Jesuits, dedicated at Montmartre in 1534...

 begs the prayers of the Goa

Goa

Goa , a former Portuguese colony, is India's smallest state by area and the fourth smallest by population. Located in South West India in the region known as the Konkan, it is bounded by the state of Maharashtra to the north, and by Karnataka to the east and south, while the Arabian Sea forms its...

 brethren for those about to start on the Japanese mission, mentioning among them Juan Fernández. On their arrival in Japan Juan was active in the work of evangelizing.

In September, 1550, he accompanied Francis Xavier to Firando (Hirado), thence to Amanguchi (Yamaguchi

Yamaguchi, Yamaguchi

is the capital city of Yamaguchi Prefecture, Japan.As of February 1, 2010, the city has an estimated population of 198,971 and a population density of 194.44 persons per km²...

), and on to Miako (Saikyo). They returned to Amanguchi, where he was left with Father Cosme de Torrès

Cosme de Torrès

Cosme de Torres , a Spanish Jesuit of the sixteenth century, was one of the first Christian missionaries in Japan. He was born in Valencia and died in Amakusa, an island now in Kumamoto Prefecture, Japan.-Early Life :...

 in charge of the Christians, when Francis Xavier started for China.

There was in the records of the Jesuit college at Coimbra

Coimbra

Coimbra is a city in the municipality of Coimbra in Portugal. Although it served as the nation's capital during the High Middle Ages, it is better-known for its university, the University of Coimbra, which is one of the oldest in Europe and the oldest academic institution in the...

 a lengthy document, professed to be the translation of an account rendered to Francis Xavier by Fernández of a controversy with the Japanese on such questions as the nature of God, creation, the nature and immortality of the soul. The success of Brother Fernández on this occasion in refuting his Japanese adversaries resulted in the ill will of Buddhist priests, who stirred up a rebellion against the local daimyo

Daimyo

is a generic term referring to the powerful territorial lords in pre-modern Japan who ruled most of the country from their vast, hereditary land holdings...

, who had become a Christian. The missionaries were concealed by the wife of one of the nobles until they were able to resume their work of preaching.

Francis Xavier says in one of his letters:

"Joann Fernández though a simple layman, is most useful on account of the fluency of his acquaintance with the Japanese language and of the aptness and clearness with which he translates whatever Father Cosmo suggests to him."

His humility under pressure impressed all and on one occasion resulted in the conversion of a young Japanese doctor, who later became a Jesuit.