Since his resignation, Benedict holds the unique title of "Pope Emeritus".
Ordained as a priest in 1951 in his native Bavaria, Ratzinger had established himself as a highly regarded university theologian by the late 1950s and was appointed a full professor in 1958.
He views relativism's denial of objective truth, and the denial of moral truths in particular, as the central problem of the 21st century.
He taught the importance of both the Catholic Church and an understanding of God's redemptive love.
His sister, Maria Ratzinger, who never married, managed Cardinal Ratzinger's household until her death in 1991.
His habilitation (which qualified him for a professorship) was on Bonaventure.
It was completed in 1957 and he became a professor of Freising College in 1958.
He attended the elementary school in Aschau am Inn, which was renamed in his honour in 2009.
As the Allied front drew closer to his post in 1945, he deserted back to his family's home in Traunstein after his unit had ceased to exist, just as American troops established a headquarters in the Ratzinger household.
; 16 April 1927) served as Pope of the Catholic Church from 2005 until his resignation in 2013.