Ninth century Byzantine chronicler Theophanes is the earliest Greek source to give a biography of Mohammed, or so I have been told. I referenced yesterday the relevant pages in the Bonn edition. But an English translation does exist, made by minor sci-fi author Harry Turtledove, although this only starts in 602 AD. This was published in 1982 so will be offline and in copyright long after I am dead, which is a pity.
Every time I find myself having to seek out an offline source, it’s a pain. I’ll only want the book for five minutes; but to get it will involved a lot of labour and time, or some money. This can’t be an unusual experience, and indicates why academic offline publishing must be doomed. It so pointless.
Another translation was made by Cyril Mango for Oxford University Press, in 1997, which starts in 284AD. It translated the De Boor text, and calls the Turtledove version “highly inaccurate” — pretty steep language. Apparently it look Mango 15 years to do. Yet the Turtledove translation is still being sold. I wonder how many copies it sells? Would the publisher sell the copyright? How much for?
I find that I have access to a DJVU version of Mango, and — bless them — that Abbyy Finereader will open it so I can scan the portion about Mohammed (on page 464). The chunk is not that long. In the meantime I’m reading Mango’s introduction.
Theophanes Confessor (d. 822) uses and continues the better known chronicle of George Syncellus. He was aristocratic in manner, addicted to sport when young, handsome and even portly in appearance. He was easy-going, a generous host, and even as a monk was not averse to taking the waters at a fashionable spa. He does not seem to have travelled much, staying in the Constantinople-Bithynia area. He openly says that he did not have a proper education, and learned his work as a scribe as part of his monastic obligation.
Where Theophanes’ chronicle differs from many is that he had access to a Syro-Palestinian source which informed him about Eastern events. He thus includes the Moslem rulers in his lists. No other Byzantine chronicler was so well equipped, nor so interested in this material, which Theophanes uses extensively. Like George Syncellus, he uses the Anno Mundi chronology and his work is a descendant of that of Eusebius of Caesarea; indeed the last such.
I will add Theophanes on Mohammed here when my OCR job finishes!
UPDATE: Here it is, translated by Cyril Mango:
 In this year died Mouamed, the leader and false prophet of the Saracens, after appointing his kinsman Aboubacharos (to his chieftainship). At the same time his repute spread abroad) and everyone was frightened. At the beginning of his advent the misguided Jews thought he was the Messiah who is awaited by them, so that some of their leaders joined him and accepted his religion while forsaking that of Moses, who saw God. Those who did so were ten in number, and they remained with him until his murder. But when they saw him eating camel meat, they realized that he was not the one they thought him to be, and were at a loss what to do; being afraid to abjure his religion, those wretched men taught him illicit things directed against us, Christians, and remained with him.
I consider it necessary to give an account of this man’s origin. He was descended from a very widespread tribe, that of Ishmael, son of Abraham; for Nizaros, descendant of Ishmael, is recognized as the father of them all. He begot two sons, Moudaros and Rabias. Moudaros begot Kourasos, Kaisos, Themimes, Asados, and others unknown. All of them dwelt in the Midianite desert and kept cattle, themselves living in tents. There are also those farther away who are not of their tribe, but of that of lektan, the so-called Amanites, that is Homerites. And some of them traded on their camels. Being destitute and an orphan, the aforesaid Mouamed decided to enter the service of a rich woman who was a relative of his, called Chadiga, as a hired worker  with a view to trading by camel in Egypt and Palestine. Little by little he became bolder and ingratiated himself with that woman, who was a widow, took her as a wife, and gained possession of her camels and her substance. Whenever he came to Palestine he consorted with Jews and Christians and sought from them certain scriptural matters. He was also afflicted with epilepsy. When his wife became aware of this, she was greatly distressed, inasmuch as she, a noblewoman, had married a man such as he, who was not only poor, but also an epileptic. He tried deceitfully to placate her by saying, ‘I keep seeing a vision of a certain angel called Gabriel, and being unable to bear his sight, I faint and fall down.’ Now, she had a certain monk  living there, a friend of hers (who had been exiled for his depraved doctrine), and she related everything to him, including the angel’s name. Wishing to satisfy her, he said to her, ‘He has spoken the truth, for this is the angel who is sent to all the prophets.’ When she had heard the words of the false monk, she was the first to believe in Mouamed and proclaimed to other women of her tribe that he was a prophet. Thus, the report spread from women to men, and first to Aboubacharos, whom he left as his successor. This heresy prevailed in the region of Ethribos, in the last resort by war: at first secretly, for ten years, and by war another ten, and openly nine. He taught his subjects that he who kills an enemy or is killed by an enemy goes to Paradise; and he said that this paradise was one of carnal eating and drinking and intercourse with women, and had a river of wine, honey, and milk, and that the women were not like the ones down here, but different ones, and that the intercourse was long-lasting and the pleasure continuous; and other things full of profligacy and stupidity; also that men should feel sympathy for one another and help those who are wronged.
 Muhammad died in 632.
 … Muhammad, of course, was not murdered. Besides, the sequence of thought appears to require something like ‘until they had seen him taking food’. The reading phaghs is not appropriate unless it can mean the act of eating rather than ‘food’, the latter given by Du Cange, Gloss., s.vv. phage, phagh. Dr R. Hoyland has drawn our attention to Chr. 819, 7, which says of Muhammad, primus fecit sacrificium, et comedendum imposuit Arabibus, praeter eorum morem. The eating of camel is forbidden in Deut. 14: 7. The story of the rabbis, of whom only two embraced Islam sincerely, whereas the others pretended to do so, is found in the Sira of Ibn Ishaq (d. 768), trans. A. Guillaume, The Life of Muhammad (London, 1955), 239 ff., 246 ff.
 These names correspond to Nizar, Mudar, Rabi`a, Quraish, Qais, Tamim, and Asad. Discussion by L. I. Conrad, ByzF 15 (1990), 11 ff. Longer genealogy in Chr. 1234, 187-8. …
 … The legend of a Christian monk, variously called Sergius, Bahlra, or Nastur, who was either the teacher of Muhammad or recognized him as a prophet, enjoyed a wide currency. See S. Gero in Syrie colloque, 47-58.
 The durations given here, although presumably derived from an Arab source, do not agree with the Muslim tradition. See L. I. Conrad, ByzF 15 (1990), 18 ff.