Anyone have any idea what this coin is? Seems to be a coin of Elagabalus/Demeter on a Biga, but I couldn't find anything that matches it in RPC. The closest reverse dies I found were from Sardis, but they're not exact: https://rpc.ashmus.ox.ac.uk/coins/4/2297, https://rpc.ashmus.ox.ac.uk/coins/4/8319
The dealer who auctioned it last December attributes it to Hieropolis in Phrygia. RPC has not yet published its Severan volumes, so Elagabalus isn't in there.
Papillon's attribution are shaky at best. (They seem to find a similar coin via acsearch or coin archives and copy-paste the descriptions, whilst updating the weights/sizes) I've looked through the dies of Hierapolis' bigas, and find that the Sardis coins are much closer stylistically. Makes sense if this doesn't fall under the published RPC Vol. 6, which includes Elagabalus coins from Asia Minor and Egypt. Didn't have any luck looking for coins via ACSearch that provided more hints, either
Here are the three RPC coins from Hierapolis with Demeter on a Biga: https://rpc.ashmus.ox.ac.uk/coins/6/5434 https://rpc.ashmus.ox.ac.uk/type/29371 https://rpc.ashmus.ox.ac.uk/type/20710 But looking at the composition of the biga, the two from Sardis seem more similar to me. Unfortunately don't own the associated standard reference works to go through and look for matches :'(
The first seems closest to the reverse design in that Demeter has a billowing veil over her head and the snake-biga is traveling left to right ... But the obverse portrait and the lettering on the reverse are totally different. I agree it's probably from a different city not yet in RPC's listings for Elagabalus.
DUDE!!!!!! EYPHKA!! I found it with an ac search for "*AKKI* Demeter" Because AKKI was the only part of the reverse legend I could be confident of!!! It's of Caracalla and it's from Gordus-Iulia in Lydia, BMC 39.
Pretty sure with that and this coin https://rpc.ashmus.ox.ac.uk/coins/4/8319 I can safely say it's safe to say it's from Iulia Gordus! Edit: taking a close look at the plate, I believe it's actually the exact same coin type as the BMC specimen, the legend fully matches