Didache (dĭdˈəkē) [key] [Gr., = teaching], early Christian work written in Greek, called also The Teaching of the Twelve Apostles. Dates for its composition suggested by scholars have ranged from A.D. 50 to A.D. 150. Discovered in 1875 by Bryennios, Greek Orthodox metropolitan of Nicomedia, it is an invaluable primary source for the primitive church. The first part is a collection of moral precepts, perhaps based on rabbinical teachings (there are many quotations from the Old Testament); the second portion gives directions for baptism and the Eucharist; the third contains directions for bishops and deacons. The Didache may be of composite authorship. A short work, it has been published in English translation in collections of patristic literature.