Saint Emmanuel was a Christian martyr who lived in Anatolia during the third and fourth centuries. He is remembered for his death in Sirmium, located in modern-day Serbia, around the year 304. His execution occurred during the widespread persecutions led by the emperor Diocletian. He was martyred alongside forty-two other individuals, including figures such as Quadratus and Theodocius, who shared his fate during this period of religious conflict.