Known to the Romans as Jupiter, Zeus was the great god of the Graeco-Roman pantheon. The coin types depict him as nude, or nearly so, bearded, and holding a sceptre. Various representations of this deity are commonly encountered on the tetradrachms of many emperors.
Curtis (1990) p. 44-45
Milne 444v Vespasian
Milne 4946 Diocletian
Curtis (1990) p. 198 coin 417
Milne 5051 Diocletian