Alexandre De Rhodes (1591-1660)

Born in France, he joined the Jesuits in 1612. A Jesuit mission had been established in Hanoi in 1615. He arrived in Hanoi in 1620. He wrote the first Vietnamese Catechism and he published the first Portuguese-Latin-Vietnamese dictionary, which was later used widely by many Vietnamese scholars to create the new Vietnamese writing system, largely using the Roman alphabet – still used today and now called Quốc Ngữ (national language).
(From Wikipedia)