Holy See / Papa Leo Quartus (Pope Leo IV)

Pope Saint Leo IV was pope from 10 April 847 to his death in 855. He is remembered for repairing Roman churches that had been damaged during Arab raids on Rome, and for building the Leonine Wall around Vatican Hill. Pope Leo organized a league of Italian cities who fought the sea Battle of Ostia against the Saracens.

Leo IV died on 17 July 855 and succeeded by Benedict III.