Pope Leo XIV has taken the reins as leader of the Catholic Church, starting his first day as Pontiff with a mass at the Sistine Chapel, during which he called his election both a cross and a blessing.

ROME — The new Chicago-raised Pope Leo XIV faces an immediate challenge in his native country: taming the brawling U.S. tribe of Catholics, riven by political divisions that have thwarted the will of his predecessors.

Pope Leo I tangled with Attila the Hun and won. Pope Leo III crowned Charlemagne as the first Holy Roman Emperor. This is the history of a legendary papal namesake.