Herennius Etruscus. AR Antoninianus. 22 mm, 2.83 g. AD 249-251. Rome. 

Q HER ETR MES DECIVS NOB C Radiate and draped bust right.
MAR PROP, Mars walking right, holding spear with his right hand and shield with his left.

RIC 139. 
Rare.

With permission of Leu Numismatik AG auction 5, Lot 1003, Sept 2018.