Factbox: Who are Egypt's Coptic Christians?

The Coptic Orthodox Virgin Mary church is seen during sunset ahead of Coptic Orthodox Easter in Cairo April 18, 2009. REUTERS/Tarek Mostafa

CAIRO (Reuters) - Pope Francis arrives in Cairo on Friday hoping to mend ties with Islamic religious leaders but his message of peace comes as Egypt’s Coptic Christian community faces unprecedented pressure from Islamic State militants who have threatened to wipe it out.

Below are some facts about Egypt’s Coptic Christians:

-- The Coptic Orthodox Church is one of oldest in the world. It is the principal Christian church in predominantly Muslim Egypt. Its members are called Coptic Orthodox, distinguishing them from Copts who converted to Catholicism and from the Eastern Orthodox, who are mostly Greek.

-- Head of the Church is Pope Tawadros II, based in Cairo. He claims apostolic authority from St. Mark, author of the second Gospel, who introduced Christianity to Egypt around 42 AD. The Coptic Church is thus nearly 2,000 years old, and predates the 7th century arrival of Islam.

-- Copts comprise about 10 percent of Egypt’s population of about 92 million, making them the largest Christian community in the Middle East.

-- The Coptic Orthodox Church has its own primary and secondary schools in many places in Egypt. There is an Institute of Coptic Studies in Cairo, a theological college connected with the institute, and a Coptic museum.

-- The Copts have suffered sectarian attacks for years and more recently have become a target of Islamic State. Three church bombings since December, in Cairo, Tanta and Alexandria, have claimed about 70 lives and have had a traumatic effect on the Coptic minority.

-- As a result of the violence, security for Pope Francis’ visit will be extremely tight. A three-month state of emergency has been introduced, troops have been ordered on to the streets and police are deployed around many churches.

-- Coptic Catholics, who number less than 150,000, comprise only a small proportion of Egypt’s Christians. Their patriarch is Ibrahim Isaac al-Sidrak.

Editing by Lin Noueihed and Tom Heneghan