Nestorianism is a branch of Christianity that claims there are two separate persons—one human, one divine—within Christ. It is named for Nestorius, the bishop of Constantinople whose rejection of the title Theotokos (God-bearer) for the Virgin Mary led to the Convening of the Council of Ephesus in 431 C.E. (See Vasiliki Limberis, “The Battle Over Mary,” sidebar to “The Favored One” BR 17:03.)