 It must have been written no earlier than 450, as he knows of the death of the Emperor Theodosius II (29 July 450).In 1895, a 16th-century book manuscript containing a copy of a text written by Nestorius was discovered by American missionaries in the library of the Nestorian patriarch in the mountains at Konak, Hakkari.This book had suffered damage during Muslim conquests, but was substantially intact, and copies were taken secretly.