I recently won this dupondius on eBay for way less than the price of a meal at a nice Italian restaurant. It helped I was the only bidder! Vespasian Æ Dupondius, 13.42g Lyon mint, 77-78 AD RIC 1211 (R). BMC 831. Obv: IMP CAES VESPASIAN AVG COS VIII P P; Head of Vespasian, radiate, r.; globe at point of bust Rev: FIDES PVBLICA; S C in field; Fides stg. l., with patera and cornucopiae Ex eBay, 23 March 2019. FIDES PVBLICA, the good faith of the state, was a common personification on Vespasian's coinage. The figure on the reverse is likely based on a cult statue of the goddess whose annual sacrifice occurred on 1 October. Important documents of state and treaties were store in her temple for safe keeping. The Fides type came into common imperial use during the Flavian era and was an important part of Vespasian's numismatic propaganda. This dupondius was struck at the Lyon mint in 77-78 in a fairly large issue that presumably addressed a shortage of bronze coinage in the Western provinces. Oddly enough, dupondii are more commonly encountered in this issue with a laureate bust instead of the usual radiate one as seen here. Post your Fides!
That's a lovely coin, @David Atherton , and a great deal! Fides is depicted on the last issue of Caracalla as Caesar before being elevated to Augustus (AD 198): Caracalla as Caesar, AD 196-198. Roman AR denarius, 2.46 g, 18.5 mm. Rome, AD 198. Obv: M AVR ANTON CAES PONTIF, bare-headed and draped bust, right. Rev: FIDES PVBLICA, Fides standing right, holding grain ears and dish of fruits. Refs: RIC 8, Cohen 83; Hill 321.
My Vespasian Fides Publica denarius is identifiable as such by legend but I am unclear how I would attribute the design to Fides if it were left to the design. When did Fides stop appearing on coins? I have a follis of Constantius I as Augustus. I have not researched the question.
The clasped hands FIDES PVBLICA refers to concord (a holdover attribute from the recent Civil War), the caduceus for commercial prosperity, and the poppy and corn-ears for good faith in the grain supply.