Æ22 - Trajan ΔΙ

The Koinon of Bithynia — the provincial council representing the federated cities of Bithynia and Pontus — issued coins bearing imperial portraits as part of its religious and civic role in maintaining the imperial cult. These koina issues were not produced by a single city mint but authorized by the provincial assembly, which had the right to strike bronze coinage granted under Roman provincial administration. The ΔΙ mark in the type designation likely indicates a die or series classification within the Waddington-Mionnet numbering tradition rather than a denomination marker.