When the world learned of Pope Francis' death on Monday morning, an Irish-American cardinal, little known in the wider world, was the one to break the news.

After announcing that the pope had "returned to the home of the Father", Irish-American Cardinal Kevin Farrell took on one of his biggest roles yet: the "camerlengo", or the person who runs the Vatican after the death or resignation of a pope.

Pope Francis nominated the cardinal for the role in 2019. The cardinal will remain in the position during the "Apostolica Sedes Vacans", the period between the death or resignation of a pope until the election of the next pontiff.

He also will play an important role in the centuries-old ceremonies to mourn Pope Francis.

Born in 1947 in Dublin, Farrell attended the University of Salamanca in Spain and the Pontifical Gregorian University in Rome, according to the Vatican.

He held roles in churches around the world, serving as a chaplain at the University of Monterrey in Mexico as well as at a parish in Bethesda, Maryland.

All told, the 77-year-old spent more than 30 years working for churches in the US.

Farrell was appointed Bishop of Dallas in 2007 until Pope Francis asked him in 2016 to serve as the leader of the Vatican's new department responsible for the pastoral care of families, raising him to the rank of cardinal.

Years after naming him as camerlengo, in 2023, Francis chose Farrell as president of the Supreme Court of Vatican City State. He was also named president of the Commission for Confidential Matters.

As camerlengo, Cardinal Farrell will be tasked with making arrangements for the conclave, the process through which the next pontiff is selected.

Technically, a camerlengo can become pope, as has happened twice in history: Gioacchino Pecci (Pope Leo XIII) in 1878 and Eugenio Pacelli (Pope Pius XII) in 1939.

The cardinal also will preside over the certification of Francis's death, laying his body into the coffin. After that, the cardinal is expected to lead a procession moving the pope's body from the chapel of the Domus Santa Marta to St Peter's Basilica.

The ceremony could take place as soon as Wednesday morning, according to the Vatican.