Joseph Cardinal Ratzinger, as of 2005 Pope Benedict XVI, was from November 25, 1981 Prefect of the Congregation for the Doctrine of the Faith, formerly known as the Holy Office, and, especially in the mid-2nd millennium, as the Roman Inquisition. He was named to that post by Pope John Paul II.

Archbishop of Munich-Freising since 1977, and a cardinal since the same year, he resigned the post of bishop in early 1982, in light of his new duties as Prefect. (He would be promoted within the College of Cardinals to become Cardinal Bishop of Velletri-Segni in 1993, and became the College's vice-dean in 1998 and dean in 2002.)

In office, Ratzinger fulfilled his institutional role, defending and reaffirming official Catholic doctrine, including teaching on topics such as birth control, homosexuality, and inter-religious dialogue. During his period in office, the Congregation for the Doctrine of the Faith took disciplinary measures against some outspoken liberation theologians in Latin America in the 1980s and Jesuit priest Anthony de Mello. In 1983, he issued Quaesitum est, also called Declaration on Masonic Associations, which drew on Clarification concerning status of Catholics becoming Freemasons (itself issued by the Congregation 9 months before his becoming its prefect). The Congregation condemned liberation theology twice (in 1984 and 1986), accusing it of Marxist tendencies and of inciting hate and violence. Leonardo Boff, for example, was suspended, while others were reputedly reduced to silence.