Nguyễn Phúc Lan

Unwilling to make peace, Nguyễn Phúc Lan continued his father's policies of maintaining a strong defensive position on the great walls while continuing friendly relations with the Portuguese and expanding south into Cambodian and Champa territory.

In 1640, famed Jesuit missionary Alexandre de Rhodes returned to Vietnam, this time to the Nguyễn court at Phú Xuân.

He began work on converting people to the Roman Catholic faith and building churches.

However, after six years, Nguyễn Phúc Lan came to the same conclusion as Trịnh Tráng had: that de Rhodes and the Catholic Church represented a threat to his rule.

De Rhodes never returned to Vietnam but Vietnamese Catholics remained and continued to practice their new religion.