St. Mercurius is known in Coptic Egyptian tradition as the "saint of the two swords." The tradition states that he was given a sword by an angel in order to fight against the barbarians. He was martyred, and after his martyrdom he appeared to Julian the Apostate during a battle against the Persians and pierced him with a sword. He is always represented in Coptic art as a horseman holding two swords. This church, dedicated to him was built in the 6th Century and underwent intensive restoration during the 12th Century. The church is actually comprised of two churches one on top of the other with many little side chapels dedicated to various saints, though they are generally no longer in use.