Æ24 - Valerian and Gallienus ΝΙΚΑΙΕΩΝ ΒΥΖΑΝΤΙΩΝ, ΟΜΟΝΟΙΑ

This bronze was struck as a homonoia issue — a formal declaration of civic harmony between Nicaea and Byzantium, two cities with a long history of commercial rivalry along the Propontis. Such alliance coins were as much diplomatic currency as actual coinage, circulated to signal a political alignment that both cities wished to advertise. The joint reign of Valerian and Gallienus, 253–260, provided a window of imperial stability that encouraged exactly this kind of inter-city posturing.

Nicaea and Byzantium had previously clashed during the crisis following the death of Septimius Severus, when Byzantium backed the losing side and suffered severe punishment. The memory of that miscalculation likely made later gestures of regional solidarity more appealing.