THE 12TH OF DECEMBER MUST BE REMEMBERED BY THE COPTS EVERY YEAR AS THEIR NATIONAL BLACK DAY – IT IS THE DAY THE ARAB INVASION OF EGYPT STARTED IN 639 AD
The Arab Conquest of Egypt was largely complete by the summer of 642 AD, and on the 17 September the Romans of the Byzantine Empire evacuated Alexandria, the capital of the Egyptian Province, and handed it over to the invading Arabs and Muslims.
The Arab occupation of Egypt had started a little more than three years earlier. The first time the invading Arabs touched with their feet the sacred Egyptian soil was in 639 AD. Arab chronology of the Arab Conquest of Egypt is generally not to be trusted as prominent historians have more than once observed; however, there is one date that can be trusted: the 10 Dhu’l Hiijja, 18 AH. On this day, according to Arab chronicles, the invading Arabs celebrated Eid al-Adha (عيد الاضحى), or the Muslim Day of Sacrifice – and they did that, under the command of their leader ‘Amr ibn al-Asi, at the most eastern Egyptian town at Egypt’s border with Palestine then, ‘Arish (العريش), known to the Greeks and Romans as Rhinocolura (Ῥινοκόρουρα).
This date, 10 Dhu’l Hiijja, 18 AH, which corresponds to 12 December 639 AD, marks the start of the Arab invasion of Egypt, and the beginning of the long occupation of our land by the Arabs and other Muslims. Without doubt it is one of the darkest days of Eternal Egypt, if not the darkest: from that day on the destruction of Egypt, our Church and our nation started in earnest. This day must be remembered in every year by all Copts, and I hope by Muslims who were forced to convert to Islam from our fold, with much sadness, tribulation, lamentation, shame and anger, inter alia, at ourselves for allowing that invasion to take place, and for permitting our beautiful and sacred country, Egypt, to be seized by the Arabian horde and be destroyed by them.
The remembrance must be accompanied by much spiritual reflection and intellectual search on how we could have averted that evil occupation. We call on all Copts to remember the 12th of December of every year as our National Black Day, the day the Arab invasion of Egypt commenced; and on this day we must mourn, reflect and think how we got it so wrong, and how we failed to defend our nation, Church and Egypt.
 On this accuracy of dating this event, read The Arab conquest of Egypt and the last thirty years of the Roman dominion by Alfred Joshua Butler (Oxford; Clarendon Press; 1902), particularly his essay “On the Chronology of the Arab Conquest” (pp. 498-507). On this date, Butler says: “This date, given by Ibn ‘Abd al Hakam, fits in so well with other known dates that it may be taken as settled.” (n. 2, p. 198)