Doctrine that emphasized the single nature (the term means literally "of one nature") of Christ, as a wholly divine being rather than part-divine and part-human. Monophysitism began to appear in the 5th cent.; though condemned as a heresy at the Council of Chalcedon (451), it was tolerated by such Byzantine leaders as Justin II, Theodora, and Zeno, resulting in a full-fledged schism between East and West. Several Monophysite churches, incl. the Coptic Orthodox Church, were founded in the 6th cent.