(from μονος, solus, and φυσις, natura), a general name given to all those sectaries in the Levant who only own one nature in Jesus Christ, and who maintain that the divine and human natures of Christ were so united as to form only one nature, yet without any change, confusion, or mixture of the two natures.

The Monophysites, however, properly so called, are the followers of Severus, a learned monk of Palestine (who was created patriarch of Antioch in 518), and of Petrus Fulgens. The Monophysites were encouraged by the Emperor Anastasius, but depressed by Justin and succeeding emperors. However, this sect was restored by Jacob Baradeus, an obscure monk, insomuch that when he died bishop of Edessa, in the year 588, he left it in a most flourishing state in Syria, Mesopotamia, Armenia, Egypt, Nubia, Abyssinia, and other countries. The laborious efforts of Jacob were seconded in Egypt and the adjacent countries by Theodosius bishop of Alexandria, and he became so famous that all the Monophysites of the East considered him as their second parent and founder, and were called Jacobites, in honour of their new chief. The Monophysites are divided into two sects or parties; the one African, the other Asiatic. At the head of the latter is the patriarch of Antioch, who resides for the most part in the monastery of St Ananias, near the city of Merdin; the former are under the jurisdiction of the patriarch of Alexandria, who generally resides at Grand Cairo, and are subdivided into Copts and Abyssinians. From the fifteenth century downwards, all the patriarchs of the Monophysites have taken the name of Ignatius, in order to show that they are the lineal successors of Ignatius, who was bishop of Antioch in the first century, and consequently the lawful patriarchs of Antioch. In the seventeenth century a small body of the Monophysites in Asia abandoned for some time the doctrine and institution of their ancestors, and embraced the communion of Rome. But the African Monophysites, notwithstanding that poverty and ignorance which exposed them to the seductions of sophistry and gain, remained firm in their principles, and made an obstinate resistance to the promises, presents, and attempts employed by the papal missionaries to bring them under the Roman yoke; and in the eighteenth century, those of Asia and Africa have persisted in their refusal to enter into the communion of the Catholic church, notwithstanding the earnest entreaties and alluring offers which have from time to time been made by the pope's legates to conquer their inflexible constancy. The Monophysites propagate their doctrine in Asia with zeal and assiduity, and have at length gained over to their communion a part of the Nestorians, who inhabit the maritime coast of India.