The principal doctrine of the Egyptian Christians, or =Copts=, is that God the Father and Christ are of =one and the Same nature=; Arius held that God and Christ are only =similar in nature=, and was declared a heretic. The Copts are called =Monophysites=, because they believed, and still believe, that Christ is of one nature only, and =Jacobites= because their views as to the nature of Christ are identical with those of one Jacob, a famous preacher of the Monophysite doctrine. The head of the Coptic Church is the =Patriarch=, who is chosen from among the monks of the Monastery of St. Anthony in the Red Sea Desert. The Copts attach great importance to =Baptism=, they face the East when praying, and they pray seven times a day. They make use of Confession, and keep five Fasts and seven Festivals. The Copts were persecuted severely in the reigns of Hadrian, Decius, Diocletian, and Julian the Apostate (A.D. 361), but the cruellest of the persecutions of the Roman emperors was that of Diocletian in 304. The Copts commemorated the sufferings of their community on this occasion by making the =Era of the Martyrs=, by which they date their documents, begin with the day of Diocletian’s accession to the throne, _i.e._, =August 29th, A.D. 284=. In the reign of Justinian the Copts split up into two great parties, _i.e._, the =Melkites=, or Royalists, which included all those who were in the service of the Government, and the =Jacobites=, or ordinary inhabitants of the country; henceforward each party chose its own Patriarch. The dissensions between them materially aided the Conquest of Egypt by the Arabs.