ARZON. - The present-day Chaldean diocese of Séert was formerly known as A. The Nestorians also called it *Mévaadré* («the dispersed»), to indicate the scattered tribes that composed II. Under the first patriarch, in 1553, it had a Catholic bishop, and the series has continued to this day with only the interruption of the last three decades of the 17th century. This diocese was devastated during the war of 1914–18 and has not yet been reorganized to this day.
BIBL.: J. Tinkdji, *L'Eglise Chaldéenne cath. autrefois et aujourd'hui*, excerpt from A. Battandier, *Annuaire Pontifical cath.*, 17 (1914), pp. 45 sq.