John of Nikiû was an Egyptian Coptic bishop of Nikiû/Pashati in the Nile Delta and appointed general administrator of the monasteries of Upper Egypt in 696. He was author of a Chronicle extending from Adam to the end of the Muslim conquest of Egypt which contains important historical details otherwise unknown.
According to the History of the Patriarchs by Severus, Bishop of Al-Ashmunyn (Heliopolis), John of Nikiû lived under the Patriarchs John of Semnûd, Isaac, and Simeon. But when John disciplined a monk guilty of some moral offence so severely that the monk died ten days later, the Patriarch Simeon removed John from his office.
John of Nikiû's Chronicle was originally written mostly in Greek except possibly some of the chapters concerning Egypt which may have been written in Coptic to judge from the forms of the names. The work only survives in an Ethiopian translation made in 1602 of an Arabic translation of the original. The text is in parts obviously corrupted with unfortunate accidental omissions. Most notably, a passage covering 30 years from 610 to 640 are missing.
The Chronicle is most noteworthy for its passages dealing with the early 7th century. John covers in detail the revolt of the Thracian armies in 602 and the subsequent overthrow of the Emperor Maurice by the usurper Phocas. His account adds considerably to our knowledge of the reign of Phocas and particularly to the successful revolt against him begun at Carthage by Heraclius. Unfortunately, the section dealing with the climactic Persian wars waged by Heraclius is not extant.
Perhaps the most important section of John's Chronicle is that which deals with the invasion and conquest of Egypt by the Muslim armies of Amr ibn al-Aas. Though probably not an eye-witness, John was most likely of the generation immediately following the conquest and is the only near-contemporary account. John describes the major events of Amr's campaign, such as the taking of the Roman fortress at Babylon and the capture of Alexandria. Though his details are often vivid, his timeline is occasionally confusing.
John credits the Muslims for not destroying Christian holy places, but he also records the numerous atrocities committed against the Egyptians and the enormous new taxes placed on the native population. In some cases, the taxes were so burdensome that families were forced to sell their children into slavery to pay them. John also does not fail to mention in harsh terms the numerous Egyptians who abandoned Christianity in favor of Islam.
Writing from a Monophysite point of view—at odds with the Christian faith affirmed at the Council of Chalcedon in 451—John describes the Islamic invasion of his homeland as divine punishment for the Chalcedonian heresy which held sway in the Roman Empire. At the close of his Chronicle John describes the despair felt by the conquered Alexandrians, writing: "None could recount the mourning and lamentation which took place in that city....And they had none to help them, and God destroyed their hopes and delivered the Christians into the hands of their enemies."