AR25 - Trajan L ΕΝΑΤΟΥ

This tetradrachm falls in Trajan's ninth regnal year by Egyptian reckoning — a dating system the Alexandrian mint maintained independently of the Roman calendar, a bureaucratic holdover from Ptolemaic administrative practice that Rome never bothered to abolish. The billon fabric of Alexandrian issues had been deteriorating since the late first century, and by this point the silver content was well below what the denomination nominally implied, though the coins circulated freely within Egypt's closed currency system, which barred outside coinage and forced all exchange through official Alexandrian product.