In 2002, the Ulaanbaatar mission was elevated to the present apostolic prefecture. The mission's superior, the late Fr. Wenceslao Padilla, a priest of the Immaculate Heart congregation, was appointed prefect, and was consecrated a bishop the following year. Padilla died in September 2018. Mongolia's first native priest was ordained in 2016.
Marengo told Vatican News in 2020 that because Mongolia's Catholic community is so small it is especially important to pay attention to interreligious dialogue and the cultural traditions of the Mongolian people.
"It means dedicating time to know and study the language, to refine those tools that allow us to enter into a true dialogue with people, to understand their points of reference, their history, their cultural and religious roots," he said.
"And at the same time, in all this, to be faithful to the Gospel itself … to offer with great humility, with great sincerity this precious pearl we have received which is the Gospel of the Lord."
Marengo grew up in Turin, Italy, studied theology at the Pontifical Gregorian University in Rome, and later obtained a license and doctorate from the Pontifical Urbaniana University.
He chose "Respicite ad eum et illuminamini" as his episcopal motto, which means "Look to him and you will be radiant."
Until the consistory in August, the current youngest cardinal is 55-year-old Cardinal Dieudonné Nzapalainga of Bangui.
Marengo will turn 48 on June 7.