Mercurius (Greek: Ἅγιος Μερκούριος, Coptic: Ⲫⲓⲗⲟⲡⲁⲧⲏⲣ Ⲙⲉⲣⲕⲟⲩⲣⲓⲟⲥ; Syriac: ܡܳܪܩܘ̇ܪܝܘ̇ܣ; 224/225 – 250 AD) was a Roman soldier of Scythian descent who became a Christian saint and martyr.

[4] Saint Mercurius was also widely known by his Arabic-language name Abu-Sayfain, Abu-Sifin or Abu-Sefein in Egyptian Arabic (Arabic: أبو سيفين, romanized: Abū Seyfaīn; Coptic: ⲁⲃⲩⲥⲉⲫⲁⲓⲛ, romanized: Abû-Sefaīn) which means "wielder of two swords", referring to the second sword given to him by the Archangel Michael.

News of their baptism spread quickly in the city and the prince ordered them to be arrested and thrown to wild animals.

Described as very strong and courageous, Mercurius earned the respect of his fellow soldiers and gained renown as a swordsman.

However, one of the guards reported his absence, and the Emperor called Mercurius and asked him: "Is it true that you refused to worship the idols who helped us during the war?

Fearing a revolt because the people loved Mercurius, the emperor had him bound in iron fetters and sent him to Caesarea.

According to one tradition, Saint Basil once prayed before an icon on which Mercurius was portrayed as a soldier carrying a spear.

He asked God not to permit the emperor Julian the Apostate (361-363) to return from his war against the Persians and resume his oppression of Christians.

The image of the holy Great Martyr Mercurius depicted on the icon became invisible, only to reappear later with a bloodied spear.

Julian the Apostate, on his Persian campaign, was mortally wounded by the spear of an unknown saracen soldier.

[5] The nuns and their abbess, Tenmav Irini at the Abu Sefein Monastery in Cairo credit the saint's intercession for the reversal of a government decision to confiscate their property for the Defense Ministry.

[12] According to local folklore, after Tamav Irini prayed for Abu Sefein's intercession, he appeared, in one way or another, to Egyptian president Hosni Mubarak.