Apostolicae Curae was basically the formalization of a consensus that Anglican orders were rendered invalid during the reign of Edward VI, Henry VIII's son. Edward's radical Protestant advisers changed the manner of consecration of bishops and ordination of priests to remove the words empowering a priest to celebrate the Eucharist and perform the "office and work" of a priest. That omission from the traditional form was intended to separate from the Catholic Church by omitting any special power of the Holy Spirit, because the radical Protestants believed in "every man his own priest" and denied any special power in ordination. So both intention and actual words severed the line of Apostolic Succession.
In 1555, after Queen Mary's accession to the throne and the return of England to Catholicism, Pope Paul IV issued the Bull Praeclara Charissimi, directing that "those who have been promoted to ecclesiastical Orders . . . by any one but a Bishop validly and lawfully ordained are bound to receive those Orders again." Apostolicae Curae also notes that converting priests were reordained in the 17th and 18th centuries, thus indicating that their orders were not valid.