Herennius Etruscus, as Caesar, AV Aureus. 250-251 AD. 

Q HER ETR MES DECIVS NOB C, bare-headed and draped bust right 
PRINCIPI IVVENTVTIS, Herennius standing left, holding rod and spear. 
RIC 147a; Cohen 25.

With permission of Numismatica Ars Classica, Sold for 
30,000 Swiss Francs.