Josef Alois Ratzinger was born to Joseph and Maria Ratzinger April 16, 1927, in Marktl am Inn, Germany. The pope's father was a policeman, and the family moved frequently during his youth. His brother Georg, who is three years older, became a priest, studied music and became director of the world-famous Regensburg boys' choir. His sister Maria, who was five years old when her brother Josef was born, looked after his household for many years and followed him to Rome.

According to his memoirs, Pope Benedict XVI was only vaguely aware of the poverty and political strife building up in Germany before the outbreak of World War II. He joined his brother, Georg, at the minor seminary in 1939. Ordained a priest in 1951, he received a doctorate and a licentiate in theology from the University of Munich, where he studied until 1957. He taught dogma and fundamental theology at the University of Freising in 1958-59, and then lectured at the University of Bonn, 1959-1969, at Munster, 1963-66, and at Tubingen from 1966 to 1969. In 1969 he was appointed professor of dogma and of the history of dogmas at the University of Regensburg, where he also served as vice president until 1977.

A theological consultant to West German Cardinal Joseph Frings, he attended the Second Vatican Council as an expert or peritus. At the council, he played an influential role in discussions among the German-speaking participants and gained a reputation as a progressive theologian. After the council, he published several major books, including Introduction to Christianity, Dogma and Revelation and Eschatology. He was named a member of the International Theological Commission in 1969. Pope Paul VI appointed him archbishop of Munich and Freising in 1977, and named him a cardinal later that year.

On November 25, 1981, Pope John Paul II named Cardinal Ratzinger prefect of the Congregation for the Doctrine of Faith, President of the Pontifical Biblical Commission and of the International Theological Commission. As the guiding light on doctrinal issues during Pope John Paul II's pontificate, Pope Benedict XVI was one of the most respected, influential and controversial members of the College of Cardinals. He was a major figure on the Vatican stage for nearly a quarter of a century.

On November 30, 2002, Pope John Paul II approved the election of Cardinal Ratzinger as the Dean of the College of Cardinals and gave him the title of Cardinal-Bishop of Ostia. Upon the death of John Paul II on April 2, 2005, Cardinal Ratzinger resigned as prefect of the Congregation for the Doctrine of Faith and prepared to participate in the Conclave to elect the next pope, which began on April 18.

On April 19, 2005, Cardinal Joseph Ratzinger was elected as the 265th Pope and the first German pope in 948 years. He adopted the name Benedict XVI, in honor of St. Benedict, the founder of Western monasticism, and of Benedict XV, pope during World War I and a promoter of peace.