The Second Vatican Council’s Constitution on the Liturgy, Sacrosanctum Concilium (SC), affirmed the continued use of Latin, but only permitted limited use of vernacular languages in the liturgy:
SC 36. 1. Particular law remaining in force, the use of the Latin language is to be preserved in the Latin rites.
2. But since the use of the mother tongue, whether in the Mass, the administration of the sacraments, or other parts of the Liturgy, frequently may be of great advantage to the people, the limits of its employment may be extended. This will apply in the first place to the readings and directives, and to some of the prayers and chants, according to the regulations on this matter to be laid down separately in subsequent chapters.
3. These norms being observed, it is for the competent territorial ecclesiastical authority mentioned in Art. 22, 2, to decide whether, and to what extent, the vernacular language is to be used; their decrees are to be approved, that is, confirmed, by the Apostolic See. And, whenever it seems to be called for, this authority is to consult with bishops of neighboring regions which have the same language.
4. Translations from the Latin text into the mother tongue intended for use in the Liturgy must be approved by the competent territorial ecclesiastical authority mentioned above.
Following the Council, the texts of the Mass and other liturgical texts, were rapidly translated into English by the International Commission on English in the Liturgy (ICEL), formed during the Council for this purpose, and hastily approved for use in English-speaking countries. Simultaneously, new Scripture translations in English were produced by several different bodies - most of which we see today as inaccurate translations.