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This Byzantine concept is a Greek-Latin hybrid: Greek kella from Latin cella, found in inscriptions from the second century a.d., identified a room or chamber especially for storage of wine, papyri, etc., whence it came to designate the “cell” of a monk. The chamber-mate, synkellos, known from the fifth century, was the ecclesiastic who shared living quarters with another. In the case the latter was a ranking prelate, the duties of the former were those of domestic chaplain, but it appears he functioned often as little more than ecclesiastical spy. Yet his association could make him an obvious choice for succession.