Claudius II died of plague in 270 AD after a reign of just under two years, but his short tenure produced a remarkable volume of Alexandrian tetradrachms — the mint was prolific even by Egyptian standards. This particular emission falls within his final regnal year, when the empire was still absorbing the military and economic shock of decades of third-century crisis. The silver content of these billon pieces had been debased so aggressively by successive emperors that "silver plated copper" is, by this point, an honest description rather than a manufacturing defect.
Claudius II died of plague in 270 AD after a reign of just under two years, but his short tenure produced a remarkable volume of Alexandrian tetradrachms — the mint was prolific even by Egyptian standards. This particular emission falls within his final regnal year, when the empire was still absorbing the military and economic shock of decades of third-century crisis. The silver content of these billon pieces had been debased so aggressively by successive emperors that "silver plated copper" is, by this point, an honest description rather than a manufacturing defect.