Judas Cyriacus was a 4th-century bishop who lived in Jerusalem. According to tradition, he was a Jewish man who assisted Empress Helena in locating the True Cross at Golgotha. Following his conversion to Christianity, he was consecrated as a bishop and eventually martyred during the persecutions under Julian the Apostate. He is widely recognized as the patron saint of Ancona, Italy, and is commemorated in both Catholic and Orthodox traditions.