He was created
Cardinal-Priest of
Santa Balbina by John Paul II in the
consistory of 21 October 2003. He was the youngest member of the
Sacred College until the appointment of
Reinhard Marx in 2010. Erdő was elected to a five-year term as president of the Hungarian Episcopal Conference in September 2005 and to a five-year term as president of the Council of Episcopal Conferences of Europe in October 2006. On 17 January 2009 he was appointed a member of the
Pontifical Council for Culture by Pope Benedict XVI, and on 29 January 2011 of the Secretariat of State (Second Section). Erdő sponsored the Thirteenth International Congress of Medieval Canon Law in Esztergom, 3–9 August 2008. On 19 October 2011, the apostolic nunciature in Peru announced that he would undertake an
apostolic visitation to intervene in the dispute between the
Pontifical Catholic University of Peru and
Juan Luis Cipriani Thorne,
Archbishop of Lima. On 18 September 2012, Erdő was appointed by
Pope Benedict XVI to be one of the Synod Fathers for the upcoming October 2012 Ordinary General Assembly of the
Synod of Bishops on the New Evangelization. On 14 October 2013, Erdő was named by
Pope Francis to serve as the Relator General of the Third Extraordinary General Assembly of the
Synod of Bishops, which took place from 5 to 19 October 2014. The chosen theme is "The challenges of the family in the context of evangelization". He resumed his appointment as Relator General when the Synod reconvened in October 2015. In the 2015 book
The Rigging of a Synod?, Vatican correspondent Edward Pentin claimed that Cardinal
Lorenzo Baldisseri had pressured Erdő to soften the wording of his 2014 address to the Synod. In 2015, Erdő's second address to the synod was described by journalists, such as
Damian Thompson of
The Spectator and
John L. Allen Jr. of the
Boston Globe, as more theologically conservative in its tone. During this speech he decried how, "the current tendency to pass off those things which are simply desires, often selfish ones, as true and proper rights, while denying the basic objective of all law, must be avoided". Erdő participated as a cardinal elector in the
2005 and
2013 papal conclaves, which elected Popes
Benedict XVI and
Francis, respectively. He had been mentioned as early as 2022 as
a potential candidate in the 2025 conclave, in which he again participated as an elector; that conclave ultimately elected
Pope Leo XIV. In March 2023, his titular church was changed to
Santa Maria Nuova after his previous titular church, Santa Balbina, was closed because of structural deterioration. Erdő is the Grand Prior of the Hungarian Lieutenancy of the
Equestrian Order of the Holy Sepulchre of Jerusalem. ==Views==