Æ37 - Gallienus (sole reign) (ΠΕΡΓΑΜΗΝΩΝ ΚΑΙ ΕΦΕϹΙΩΝ ΟΜΟΝΟΙΑ, ΕΠΙ ϹΕΞ ΚΛ ϹΕΙΛΙΑΝΟΥ)

This coin belongs to a category of homonoia issues — pieces struck jointly by two cities to commemorate their political and religious concord. The pairing of Pergamum and Ephesus was among the most prestigious in the province of Asia, both cities having long competed for the title of "First City" of the province and the privileges that came with it. Striking a shared homonoia issue was partly a diplomatic performance, a way of staging civic harmony while the rivalry quietly continued.

The magistrate named in the legend, Sex. Cl. Seilianus, anchors this to a specific administrative moment under Gallienus's sole reign after Valerian's capture by Shapur I in 260.