Cardinal Dominique Joseph Mathieu, the Archbishop of Tehran-Isfahan, is a Belgian Franciscan friar known for his outreach to Muslims and calls for peace in a volatile region.

Born on June 13, 1963, in Arlon, Belgium, Mathieu grew up in Damme, near Bruges. He entered the Franciscan order in 1983 and was ordained a priest in 1989 after studying theology in Rome at the Pontifical Theological Faculty of St. Bonaventure.

From 1989 to 2013, Mathieu held various positions in Belgium, including vocational promoter, secretary, vicar, and provincial minister of the Belgian province of Friars Minor Conventual, rector of the national shrine of Saint Anthony of Padua in Brussels, director of the Confraternity of Saint Anthony, and president of the Central Europe Federation of the Friars Minor Conventual

In 2013, he was sent on mission to Lebanon, where he was incardinated in the provincial custody of the East and the Holy Land. There he served as custodial secretary, formator, master of novices, and rector of postulants and candidates.

From 2019 to 2021, he was definitor general and general assistant for the Central Europe Federation of the Friars Minor Conventual.

On January 8, 2021, Pope Francis appointed Mathieu as the Archbishop of Tehran-Isfahan, making him the head of the sole Latin Rite diocese in Iran, a significant appointment as the see of Tehran-Isfahan had been vacant for several years prior.

His episcopal ordination took place on February 16, 2021, in Rome. Co-consecrators were Cardinal Leonardo Cardinal Sandri, then-prefect of the Congregation for the Oriental Churches, Cardinal Mauro Cardinal Gambetti, Archbishop Ignazio Bedini, emeritus of Ispahan. The ordination took place in the Basilica of the Twelve Holy Apostles in Rome.

On October 6, 2024, Pope Francis announced that Archbishop Mathieu would be elevated to the cardinalate. The appointment was seen as important for strengthening dialogue with Iran, especially in the context of ongoing tensions in the Middle East.

Archbishop Mathieu, who took part in the Synod on Synodality, is known for his experience in interreligious dialogue and his affinity for the Islamic world. He has called for unity and an end to power struggles in the Middle East, urging world leaders to “abandon supremacy” and embrace authentic encounters with others. He also has a passion for astronomy.

Regarding languages, Archbishop Mathieu is reported to speak five languages, including French, Arabic, and English.