Constantine 8.07.010 (2)

Constantine
Obv IMP CONSTANTINVS AVG
(R.laur.cuir)
Rev SOLI INVICTO COMITI
(Sol raising right hand, holding up globe with left)
S |P
MSN in ex
London
Not in RIC (although it is mentioned in a footnote on Volume VII, p 101).
LMCC 8.07.010 (2) (RR)
3.0g, 19.1 mm x 21.5 mm
(ex Carine Hazelart)
(We will never know if MSN was a deliberate mint mark for the London mint, or whether it was an engraver's error. Only 7 coins are known with this mint mark, which would suggest an error. However, there are examples with both a Constantine and Licinius obverse, which might suggest that the use of the MSN mint mark was deliberate. In all, 4 obverse dies are known for this issue and 2 reverse dies. See "A New London Mint mark for Constantine the Great" : Numismatic Circular, July 2009, pp.106 (Lee Toone). LMCC has a further comment on this mint mark on page 64.

This coin has the same reverse die as the Licinius example in my collection. This gives a glimpse into the working practices of the mint. It suggests that reverse dies were mixed and matched and weren't exclusively used for the coins of only one emperor.)