When this ex- @Stevearino coin came up at a recent @John Anthony auction, I found it intriguing. Constantine I, AD 307-337. Roman billon follis, 6.38 g, 25.3 mm, 1 h. Trier, Autumn 307-end 308. Obv: IMP CONSTANTINVS P F AVG, laureate, draped and cuirassed bust, right, seen from rear. Rev: MARTI PATRI CONSERVATORI, Mars standing right, holding inverted spear and resting hand on grounded shield, S|A//PTR. Refs: RIC vi, p. 217, 774; Cohen 359; RCV 16002. MARTI PATRI CONSERVATORI is a title not previously used on Roman coins. Here, Constantine is likened to Mars because of his defeat of the Franci and Alemanni.* This reverse type was primarily used in Trier and Lugdunum, and it antedates Constantine's assumption from Caesar to Augustus. This coin (Triskeles sale 22, lot 530, 15 Dec 2017), was issued for Constantine I as Caesar. Note it has a laureate and cuirassed bust type, seen from the front. The coin then appears with the same bust type after Constantine's promotion to Augustus (Naumann Auction 9, lot 772, 3 Nov 2013). Mine has a different bust type -- perhaps used subsequently -- depicting Constantine laureate, draped and cuirassed and seen from the rear. Mine's a bit worn to fully appreciate this, but it is better seen on this example from CNG. Post anything you feel is relevant! ~~~ *Stevenson, Seth William, et al. A Dictionary of Roman Coins, Republican and Imperial. G. Bell and Sons, 1889, p. 540.
A nice new acquisition! I very much like the earlier, not-so-common AE types of Constantine. Constantine I, Roman Empire, AE1 ("follis"), 309 AD, Trier mint. Obv: IMP CONSTANTINVS PF AVG; bust of Constantine I, laureate, cuirassed, r. Rev: MARTI PATRI CONSERVATORI; Mars, nude, helmeted, standing r., leaning on reversed spear with r. hand and placing l. hand on shield; in fields, T-F; in exergue, PTR. 27mm, 5.94g. Ref: RIC VI Treveri 830. Constantine I, Roman Empire, AE2, 312–313 AD, Rome mint. Obv; IMP CONSTANTINVS PF AVG; bust of Constantine, draped and laureate, r. Rev: SPQR OPTIMO PRINCIPI; legionary eagle between two standards; in exergue, RP. 23.5mm, 3.43g. Ref: RIC VI Rome 348a.
As Augustus, cuirassed, from the front: It also comes as a half-follis with shorter legends, although this is typically given a later date (310-311). Do you know why? I would have expected them to be part of the same series.
Constantine I Ae Half Follis Trier 310-311 AD Obv. Bust right laureate and cuirassed Rv Sol standing facing head left. RIC 899 2.18 grms 17 mm Photo by W. Hansen I bought this little guy over 10 years ago when I was still at the time trying to maintain a rather large group of the coins of Constantine. What impressed me about this coin is the absolute freshness of the dies particularly on the obverse. The reverse is overall almost as nice except that the mintmark PTR is rather smushed. On rare occasions Constantine would mint these "half follis" coins. Given that the differences between the imagery on this coin and the contemporary follis is pretty small I would suspect that it was not a success.
I've got a similar one to you! PLG though, and it's what I assume to be a full follis, at a solid 22mm. I like yours better.
Here's one with a truncated reverse legend: London mint, A.D. 307-310 RIC 108 Obv: IMP CONSTANTINVS P F AVG Rev: MARTI PAT-RI PROPVG - Mars, holding transverse spear and shield PLN in exergue 24 mm, 7.4 g.
R.C. Those are interesting coins of Constantine I from the Trier Mint ! I've never had an example depicting Mars in a stationary pose like your 1st coin posted, but I have had a few depicting Mars in the charging pose like the coin gsimonel posted. Pictured below is the last one I acquired. Constantine I, AD 307/310-337, Trier Mint, 1st Officina. AE Follis: 26 mm, 6.65 gm, 6 h. Struck AD 307-308. RIC VI 776. Ex Spink 169, July 2004. The example pictured below I sold at CNG 483, lot 519, for $177.00. AE Follis: 26 mm, 5.42 gm, 6 h. The coin pictured below is my favorite from the Trier Mint . Constantine I as Caesar, AD 306-309, Struck c. summer 307, Trier Mint. AE Follis: 29 mm, 8.73 gm, 6 h. Ex CNG Inventory #774824, July 2006.