Newly installed Pope Leo XIV will hold a Mass with cardinals in the Sistine Chapel, a day after he was elected as the surprise choice to be the leader of the Catholic Church, becoming the first U.S. pontiff.

Cardinal Robert Francis Prevost – now known as Pope Leo XIV — is the first pope from the United States. The 69-year-old from Chicago is known as a leader with global experience. He spent much of his career as a missionary in South America and most recently led a powerful Vatican office for bishop appointments.