Who are Egypt's Coptic Christians?

Egypt's Copts, targeted in a church bombing that killed 23 people in Cairo on Sunday, are the Middle East's largest Christian minority community, and also one of the oldest.

Making up about 10 percent of Egypt's population of 90 million, the Coptic Orthodox are the largest Christian denomination in the Muslim-majority country.

Here is a recap of their history, their status today and past attacks against the minority.

- 'Dawn of Christianity' -

The Copts go back to the dawn of Christianity, at a time when Egypt was integrated into the Roman, then Byzantine empires, following the end of the dynasty of the Pharaoh Ptolemy, who was of Greek origin.

The word "Copt" has the same roots as the term "Egyptian" in ancient Greek.

Their decline started with the Arab invasions of the 7th century and the progressive Islamisation of the country, which today is largely Sunni Muslim.

The Bible says Joseph, Mary and Jesus sought refuge in Egypt after Christ's birth to escape a massacre of newborns ordered by King Harod.

Several churches and monasteries in Egypt are believed to be built on sites visited by the Holy Family during its flight.

- Copts today -

Copts are present across the whole country, with the strongest concentration in middle and southern Egypt, and are represented in all social classes.

Most adhere to the Coptic Orthodox Church of Alexandria, headed since 2012 by Pope Tawadros II, while a minority is divided between the Coptic Catholic and various Coptic Protestant churches.

Tawadros, who succeeded pope Shenuda III, was chosen after a blindfolded altar boy picked his name from a chalice, according to custom.

The Catholic Copts, who form part of the Church's eastern rites, are headed by patriarch Ibrahim Isaac Sidrak since 2013.

Vatican records show some 165,000 Catholic Copts lived in Egypt in 2010.

Weakly represented in government, Copts complain that they are sidelined from many posts in the justice system, universities and the police.

Authorities often refuse to issue building permits for churches, arguing it would disturb the peace with their Muslim neighbours.

- Deadly violence -

Egypt's Copts have also been the target of deadly violence after the 2011 uprising that toppled president Hosni Mubarak and the 2013 ouster of his elected Islamist successor after just one year of rule.

Islamist supporters of ousted president Mohamed Morsi accused the Christian community of supporting his overthrow.

They pointed to the appearance of Tawadros alongside President Abdel Fattah al-Sisi in July 2013, when the then army chief, also surrounded by Muslim and opposition figures, announced on television Morsi's removal.

More than 40 churches were attacked nationwide in the two weeks after the deadly dispersal by security forces of two pro-Morsi protest camps in Cairo on August 14, 2013, Human Rights Watch said.

Amnesty International said in October 2013 that more than 200 Christian-owned properties had been attacked and 43 churches seriously damaged, adding that at least four people were killed.

In October 2011, almost 30 people -- mostly Coptic Christians -- were killed after the army charged at a protest outside the state television building in Cairo to denounce the torching of a church in southern Egypt.

In May 2011, clashes between Muslims and Copts left 15 dead in the popular Cairo neighbourhood of Imbaba where two churches were attacked.

In March the same year, 13 people were killed in clashes between Muslims and Copts in Cairo's working class neighbourhood of Moqattam, where around 1,000 Christians had gathered to protest over the torching of a church.

On January 1, 2011, the unclaimed bombing of a Coptic church killed more than 20 people in Egypt's second city of Alexandria.