Constantine I, AE follis, Trier. 16mm, 3.36g. Struck AD 318-319.

IMP CONSTAN-TINVS MAX AVG, helmeted, laureate and cuirassed bust right
VICTORIAE LAETAE PRINC PERP, two Victories holding shield inscribed VOT PR over altar. Altar type Helvetica 6C (a cross).
Mintmark: STR

RIC VII Trier 213 var (altar decoration), scarce.

With permission of Bertolami Fine Arts - ACR Auctions - E-Auction 61, Lot 657, Sept. 2018.

I know of two other examples of this type with a cross 
instead of the expected star:
One sold on ebay in May 2008 by rustyromans
One sold on ebay in July 2009 by George Clegg (biggyg2). The latter was previously here on wildwinds but has been 
replaced by this clearer example sold by Bertolami.