20 Nummi - Anastasius I Dicorus Nicomedia, Type ⁑, Large Module

Anastasius I's currency reform of 498 AD was one of the most significant monetary restructurings in late Roman history — the introduction of the large follis and its fractions ended nearly a century of debased, near-worthless small copper coinage that had made everyday transactions absurdly cumbersome. The 20 nummi piece was part of that new denominational hierarchy, struck at Nicomedia under the reformed system.

The Nicomedia mint, designated NIK in its issues, had operated continuously since Diocletian's tetrarchic reorganization. The "Large Module" designation reflects the deliberate weight standard Anastasius enforced — a standard his successors Justin I and Justinian I would inherit but struggle to maintain consistently.