Azymites

Azymites (from ἀ negative and ζύμη leaven), a title applied by the Greeks to the Western Church, because it uses unleavened bread in the Eucharist. The Greek Church has always maintained the use of leavened bread (Conf. Ecc. Orient. c. 9). The practice in the Latin Church of consecrating with unleavened bread was one of the charges brought against that Church by the Greeks in the middle of the eleventh century, and there does not appear to have been any dispute on the subject between the two churches much before that period. Indeed Sirmondus maintains that the use of unleavened bread in the holy Eucharist was unknown to the Latin Church before the tenth century, and his opinion has the support of Cardinal Bona (Per. Litur. 1, 23), Schelstrat, and Pagi. — Bingham, Orig. Eccles. bk. 15, ch. 2, § 5.