Thessalonica in Macedonia, 249-251 AD., Trajan Decius, AE 30, Touratsoglou 4.

Thessalonika in Macedonia, Trajan Decius, 249-251 AD.,
Æ30 (29-30 mm / 20.23 g),
Obv.: AYTO KAIC KYIN - TPAIANO[C ΔЄKIOC] , radiate, draped and cuirassed bust of Trajan Decius right, seen from behind.
Rev.: ΘЄCCAΛONЄIKH KO - ΛΩ MHTPOΠO Δ NЄWKOPOC , turreted Tyche / City goddess seated left on chair, holding small figure of Victory in her right hand and cornucopia with her left.
Touratsoglou p. 303, no. 4 (knew only a single specimen of your particular coin, from the same dies, namely Numismatica 21, Vienna, 1978, 382).

Curtis Clay:
The coins of Decius and family at Thessalonika are rare, and of exceptional historical importance. As R. Ziegler has shown, they demonstrate that Decius' vanquishing of Philip must have taken place near Beroea in Macedonia, as a single late Greek author reports, not at Verona in N. Italy, as all of the Latin authors state, an error in which most modern historians have followed them.

Thessalonica is merely neokoros on the coins of Philip I and family, but under Decius it receives a huge and totally unprecedented increase in its status: suddenly it becomes FOUR TIMES Neokoros, COLONY, and, instead of Beroea, the former Metropolis of Macedonia, METROPOLIS!

There is only one course of events, Ziegler suggests, that could explain such lavish honoring of Thessalonica by Decius. Decius' confrontation with Philip must have taken place in Macedonia, and Philip will have established himself in Beroea, the capital of the province. Thessalonica, Beroea's rival and neighbor, however, must have opted to side with Decius, receiving and provisioning his army and so providing essential aid for his victory over Philip. "Beroea" is written very much like "Verona" in Greek, and was obviously misread in that way by a Latin author, whose mistake was then repeated by all of the surviving Latin sources!