The papal tiara, which in the three-tiered form that it took in the 14th century is also known as the triple tiara, the triple crown or the triregnum (Latin), is a crown that was worn by popes of the Roman Catholic Church from perhaps as early as the 8th century to the 20th. It was last used by Pope Paul VI.

From 1143 to 1963, the papal tiara was solemnly placed on the pope's head during a papal coronation. The surviving papal tiaras are all in the triple form, the oldest being of 1572, and the others no earlier than 1800.

A representation of the triple tiara combined with two crossed keys of Saint Peter continues to be used as a symbol of the papacy and appears on papal documents, buildings and insignia.

The papal tiara originated from a conical Phrygian cap or frigium. Shaped like a candle-extinguisher, the papal tiara and the episcopal mitre were identical in their early forms.

Names used for the papal tiara in the 8th and 9th centuries include camelaucum, pileus, phrygium and pileum phrygium.

The Venerable Pope Pius XII (Latin: Pius PP. XII; Italian: Pio XII), born Eugenio Marìa Giuseppe Giovanni Pacelli (2 March 1876 – 9 October 1958), reigned as Pope, head of the Catholic Church and sovereign of Vatican City State, from 2 March 1939 until his death in 1958.

Before election to the papacy, Pacelli served as secretary of the Department of Extraordinary Ecclesiastical Affairs, papal nuncio and Cardinal Secretary of State, in which capacity he worked to conclude treaties with European and Latin American nations, most notably the Reichskonkordat with Nazi Germany. The concordat of 1933 which saw the self-destruction of the Centre (Catholic) Party, on the orders of the Holy See, and Pius' leadership of the Catholic Church during World War II, including his "decision to stay silent in public about the fate of the Jews", remain the subject of controversy.

After the war Pius XII advocated peace and reconciliation, including lenient policies towards Axis and Axis-satellite nations. The Church experienced severe persecution and mass deportations of Catholic clergy in the Eastern Bloc. In light of his overt involvement in Italian politics – anyone who voted for a Communist candidate in the 1948 elections was threatened with automatic excommunication – Pius XII became known as a staunch opponent of the Italian Communist Party. Pius XII explicitly invoked ex cathedra papal infallibility with the dogma of the Assumption of Mary in his 1950 Apostolic constitution Munificentissimus Deus. His magisterium includes almost 1,000 addresses and radio broadcasts. His forty-one encyclicals include Mystici Corporis, the Church as the Body of Christ; Mediator Dei on liturgy reform; and Humani generis on the Church's positions on theology and evolution. He eliminated the Italian majority in the College of Cardinals in 1946.

Paul VI (Latin: Paulus PP. VI; Italian: Paolo VI), born Giovanni Battista Enrico Antonio Maria Montini (26 September 1897 – 6 August 1978), reigned as Pope of the Catholic Church from 21 June 1963 until his death on 6 August 1978. Succeeding Pope John XXIII, who had convened the Second Vatican Council, he decided to continue it. He fostered improved ecumenical relations with Orthodox and Protestants, which resulted in many historic meetings and agreements.

Montini served in the Vatican's Secretariat of State from 1922 to 1954. While in the Secretariat of State, Montini and Domenico Tardini were considered as the closest and most influential co-workers of Pope Pius XII, who named him in 1954 Archbishop of Milan, the largest Italian diocese, yet denying him the Cardinal designation that traditionally accompanies being Archbishop of Milan, a function which made him automatically Secretary of the Italian Bishops Conference. John XXIII elevated him to the College of Cardinals in 1958, and after the death of John XXIII, Montini was considered one of his most likely successors.

Benedict XVI (Latin: Benedictus PP. XVI; Italian: Benedetto XVI; German: Benedikt XVI.; born Joseph Aloisius Ratzinger on 16 April 1927) is the 265th Pope, a position in which he serves dual roles as Sovereign of the Vatican City State and leader of the Catholic Church. As pope he is regarded as the successor of Saint Peter. Benedict XVI was elected on 19 April 2005 in a papal conclave, celebrated his Papal Inauguration Mass on 24 April 2005, and took possession of his cathedral, the Archbasilica of St. John Lateran, on 7 May 2005. A native of Bavaria, Pope Benedict XVI has both German and Vatican citizenship.

After a long career as an academic, serving as a professor of theology at various German universities—the last being the University of Regensburg—he was appointed Archbishop of Munich and Freising and cardinal by Pope Paul VI in 1977. In 1981, he settled in Rome when he became Prefect of the Congregation for the Doctrine of the Faith, one of the most important dicasteries of the Roman Curia. From 2002 until his election as Pope, he was also Dean of the College of Cardinals, and as such the primus inter pares among the cardinals. Prior to becoming Pope, he was "a major figure on the Vatican stage for a quarter of a century" as "one of the most respected, influential and controversial members of the College of Cardinals"; he had an influence "second to none when it came to setting church priorities and directions" as one of Pope John Paul II's closest confidants.