St. Callistus I lived in the late second century, early third century. Although he was born a slave, he eventually became a free man. Pope Zephyrinus had Callistus lead the Roman public burial grounds, now called the Cemetery of St. Callistus. The saint became an archdeacon and was elected the 16th pope circa 218. He died for his faith circa 223. St. Callistus is patron saint of people who work at cemeteries.