French missionaries had been active in Vietnam since the seventeenth century, and by the middle of the nineteenth century there were perhaps 300,000 Catholic converts in Annam and Tonkin.
Para misionaris Prancis telah aktif di Vietnam sejak abad ketujuh belas, dan pada pertengahan abad kesembilan belas mungkin ada 300.000 orang yang bertobat di Annam dan Tonkin.