Potin Tetradrachm, Alexandria mint, 7.9g, CE 288-289
O: laur dr bust rightA K ΓOVAΛ ΔIOKΛHTIANOC C Є B
R: Alexandria stg l holds bust of Sarapis and sceptre
Emmett 4025 (1)
Diocletian ceased minting Greek Imperial issues from Alexandria in CE 296 whereby Alexandria then began issuing standard imperial coinage and continued into the Byzantine era until the Muslim conquest (when it continued work under its new rulers).