Caligula Gaius AR Denarius. Lyons. 37-38 AD.

C CAESAR AVG GERM P M TR POT - Laureate head of Gaius Caligula, right. AGRIPPINA MAT C CAES AVG GERM - Draped bust of Agrippina wearing hair
in a queue behind. 

RIC I, 14 Rare; BMC 15; Sear5 1825, page 361

With permission of Numismatica Ars Classica, sold for 4,500 SFr.