Gordian III and Tranquillina, AE28 Pentassarion of Istros, Thrace.

Obv: AVT K M ANT GORDIANOC CAB TRANKILINA, laureate, draped 
bust of Gordian right, vis-à-vis draped bust of Tranquillina 
left.
Rev: ICTRIHNEN, Mitras on horseback right, small altar 
before, (bird perched on tall column, off flan to left), 
value mark E in exergue.

Varbanov 690; Pick 526.

Used with permission of CNG coins, www.cngcoins.com, Jan, 2011