Denarius

Obverse

Obverse legend

Reverse legend

Reverse

KAROLVS - IMP AVG (laureate and draped bust of Charlemagne to the right. The letter V under the bust).

XPICTIANA RELIGIO (circular legend around a tetrastyle temple on two degrees and surmounted by a cross (separating the letters O and X). A cross in the middle of the temple).

Photo of the copy preserved at the Bibliothèque Nationale de France (public domain), link to the page of their website showing the photo of the coin: http://www.smb-digital.de/eMuseumPlus?service=ExternalInterface&module=collection&objectId=2439919&viewType=detailView.

This type is known with a letter under the bust, indicating the mint: C for Cologne, F for Florence, M for Milan and V for Venice.

Seems never to have gone on sale.