Originally Joseph Ratzinger , a noted conservative theologian before his election in 2005, Benedict XVI strove against the influence of secularism during his papacy to defend traditional Catholic teachings but since medieval times first resigned in 2013.

After Joseph Ratzinger served a long career as an academic and a professor at the University of Regensburg, Pope Paul VI appointed him as archbishop of Munich and Freising and cardinal in 1977. In 1981, he settled in Rome as prefect of the congregation for the doctrine of the faith, one most important office of the Roman curia. He also served as dean of the college of cardinals.

Benedict XVI reigned 265th in virtue of his office of bishop of Rome, the sovereign of the state of Vatican City and the head of the Church. A conclave named him on 19 April 2005; he celebrated his inaugural Mass on 24 April 2005 and took possession of his Lateran cathedral basilica of Saint John on 7 May 2005.

Benedict XVI succeeded Saint John Paul II, predecessor and his prolific writings on doctrine and values. Benedict XVI advocated a return to fundamental Christian values to counter the increase of many developed countries. Relativism denied objective truth and moral truths in particular; he viewed this central problem of the 21st century. With the importance of the Church, he understood redemptive love of God. He reaffirmed the "importance of prayer in the face of the activism" "of many Christians engaged in charitable work." Benedict also revived a number and elevated the Tridentine Mass to a more prominent position.

Benedict founded and patronized of the Ratzinger foundation, a charitable organization, which from the sale of books and essays makes money to fund scholarships and bursaries for students across the world.

Due to advanced age on 11 February 2013, Benedict announced in a speech in Latin and cited a "lack of strength of mind and body" before the cardinals. He effectively left on 28 February 2013.As emeritus, Benedict retained the style of His Holiness, and the title and continued to dress in the color of white. He moved into the newly renovated monastery of Mater Ecclesiae for his retirement. Pope Francis succeeded him on 13 March 2013.

(more info on Ratzinger Foundation: https://www.ewtn.com/library/Theology...)