Nestorian Church, Christian community of Iraq, Iran, Lebanon, Syria, USA,  and Malabar, India. It represents the ancient church of Persia and is sometimes called the Assyrian (or East Syrian) Church. It numbers about 300,000, including emigrants to the United States. It has much in common with other Eastern rites. The liturgy (said in Aramaic/Syriac) is probably of the oldest liturgies in existence; the rite is called Assyrian. The churches are not much ornamented, but the Nestorians offer great honors to the Cross. A unique feature of their worship is their “holy leaven,” an altar bread they believe is derived from dough used at the Last Supper. The theology of the church is strictly based on the Bible and has remained unchanged throughout the centuries of the messianic faith. Its members venerate Nestorius as a saint, deny the Virgin the title Mother of God while otherwise honoring her highly, and reject the ecumenical councils after the second. The ancient Persian church was the only one to espouse the cause of Nestorius; as a result it lost communion with the rest of Christendom. The head of the church, called the patriarch of the East. The church has relations with some Jacobites and some Anglicans; in 1994 the Nestorian and Roman Catholic churches signed a declaration recognizing the legitimacy of each other's theological positions. Among the Nestorians lives a community in communion with the pope, known as Chaldean Catholics. They have rite and practices in common with the Nestorians, but have had a separate church organization since the 16th cent.  The great period of expansion of the Nestorian church was from the 7th to the 10th cent., with missions to China and India. A famous monument in Xi'an, China, was constructed (781) by Chinese Nestorians. The missions were destroyed and the church reduced through persecution by the Chinese, the Hindus, and the Muslims. In the 19th and early 20th cent., there were terrible massacres of Nestorians (Assyrians) by Kurds and Turks.

See J. Joseph, The Nestorians and Their Muslim Neighbors (1961); W. C. Emhardt and G. M. Lamsa, The Oldest Christian People (1926, repr. 1970); N. Garsoian and T. Mathews, ed., East of Byzantium (1982).