DIACONICON

diaconicon, in the greek church, the name given to a chamber on the south side of the central apse, where the sacred utensils, vessels, &c., of the church were kept. in the reign of justin ii. (565-574), owing to a change in the liturgy, the diaconicon and protheses were located in apses at the east end of the aisles. before that time there was only one apse. in the churches in central syria of slightly earlier date, the diaconicon is rectangular, the side apses at kalat-seman having been added at a later date. diadochi (gr. [greek: diadechesthai], to receive from another), i.e. "successors," the name given to the macedonian generals who fought for the empire of alexander after his death in 323 b.c. the name includes antigonus and his son demetrius poliorcetes, antipater and his son cassander, seleucus, ptolemy, eumenes and lysimachus. the kingdoms into which the macedonian empire was divided under these rulers are known as hellenistic. the chief were asia minor and syria under the seleucid dynasty (q.v.), egypt under the ptolemies (q.v.), macedonia under the successors of antigonus gonatas, pergamum (q.v.) under the attalid dynasty. gradually these kingdoms were merged in the roman empire. (see macedonian empire.) diagonal (gr. [greek: dia], through, [greek: gonia], a corner), in geometry, a line joining the intersections of two pairs of sides of a rectilinear figure.