Mercurius was a Roman soldier of Scythian descent who became a Christian saint and martyr. He was born in the city of Eskentos in Cappadocia, in Eastern Asia Minor. According to Christian tradition, he was the soldier who killed Julian the Apostate during his campaign in Persia. Mercurius was also widely known by his Arabic-language name Abu-Sayfain, Abu-Sifin or Abu-Sefein in Egyptian Arabic which means "wielder of two swords", referring to the second sword given to him by the Archangel Michael.
