Obv. Radiate head of Nero right.

Rev. Poppaea (c. AD 31 - 65), draped bust right, a loose tendril escapes the "pony-tail" of bound hair at the back of her neck. AD 64 - 65 (dated LIA = year 11 of the emperor's reign).

In AD 20 Tiberius issued new debased silver (billon) tetradrachms in Alexandria. The silver content of these tetradrachms were fixed as equivalent to that of denarii and displayed regnal dates based on the Alexandrian calender. To balance income and expenditure for the emperor's grandiose building programme in the aftermath of the great fire in Rome (AD 64), Nero debased the Alexandrian tetradrachm further by recoining the existing currency supply to the current denarius. Excess silver recovered in the process was used to coin denarii for the restoration of Rome.

Further debasement of Alexandrian coinage took place during the reign of Marcus Aurelius, producing an alloy of reduced silver content called potin (a tin-rich bronze). Tetradrachms also varied in size - whereas silver tetradrachms under the Ptolemaic reign measured around 28 mm, by the time of Diocletian billon tetradrachms measured only about 18 mm. The billon tetradrachms of Alexandria were finally discontinued by Diocletian in AD 296.
The tetradrachms displayed above are, from left to right, from the reigns of Claudius; Nero; Aurelian, and Probus.