The Chronicle of John, Bishop of Nikiu (late 7th Century), only comes down to us through an Ethiopian manuscript - it was most likely originally written in Greek (some sections might have been in Coptic). His Chronicle, an universal history beginning with creation, is an extraordinarily important chronicle for its later sections concerning the Muslim invasion of Egypt. Sadly, it is missing the important years of 610-640 AD, "from the accession of Heraclius to the arrival of the Arabs before Babylon in Egypt" (2). This Chronicle is mainly an annal (a year by year account of events).
Despite the annalistic format, it is rife with great stories including Emperor Nero's supposed pregnancy. Because Nero has married a young boy (as a woman) he is cursed by God with a disease that caused his stomach to swell. His doctors though he was pregnant so they cut him open and he died. John of Nikiu is appealing to a body of anti-pagan conceptions of bodily disease and disgust to characterized what Medieval and Late Antique writers considered the first persecutor of Christians. This is a fascinating history, mainly for its section on the Muslim conquest, and a very worthwhile purchase for the medieval or Late Antique specialist even in this 1916 re-print edition (somewhat lacking in notes and introduction).