Nestorius became Patriarch of Constantinople in 428. His theological views on the union of the human and divine natures in the one person of Jesus Christ led him to denounce the use of the term ÒMother of GodÓ as well as other language which tended to ascribe divine attributes to the humanity and human attributes to the divinity of Christ such as ÒGod diedÓ or ÒGod was bornÓ. Nestorius was opposed by Cyril of Alexandria, who was largely motivated by rivalry with Constantinople. Through CyrilÕs political machinations, Nestorius was condemned unheard at the Council of Ephesus in 431. In exile he wrote a defense of his beliefs under a pseudonym before he died. The original Greek of the ÒBook of HeraclidesÓ was lost but a Syriac translation survived in a single manuscript. Although the Assyrian Church of the East had no personal contacts with Nestorius it refuses to accept his condemnation and considers him an orthodox theologian. This volume contains an English translation of the Syriac text.