TYPE Byzantine Empire, Constantine VII Porphyrogennitos (913-959 AD), cast bronze of Cherson, 1st issue (913-9 AD) DESCRIPTION . Obv: Crowned bust of emperor in chlamys facing Rev: Large KO (kappa - omega) REFERENCE: SB 1771, An 398 GRADING: VF / G, brown patina, scarce ORDER INFO: B1644, $90 The cast bronzes of the Cherson mint in the Crimea have always been somewhat of a mystery, as their design, production method and denomination have appeared to be outside the mainstream Byzantine monetary system.