NOT IN RIC
UNLISTED ISSUE. Minted probably in year 315 when Constantine arrived to Rome to celebrate his decennalia. At the same time the great triumphal arch was finished, dedicated to Constantine as LIBERATORI VRBIS. Omitted in RIC VI and VII but was previously well known to many scholars.
Cohen lists this type for Constantine (Cohen, vol. VII, p. 265, no. 317) and also for Licinius (Ibid., p. 201-202, no. 132-133): with R*S or RS (Rome) and ALE (Alexandria) in exergue.
DRC mentions this issue in the paper "LIBERATOR ORBIS": "-The Liberator of the World.-This new title, and sufficiently assumptive, appears on a third brass of Constantine the Great, the type which it accompanies being that of the Emperor on horseback with his right hand raised, and a lion crouching under his horse's feet. -Eckhel refers it to the successes of Constantine over either his rivals or the barbarians whose incursions were pernicious to the whole Roman world, and who therefore on this medal are shadowed forth under the image of a lion trampled upon by a horseman" (p. 517).
Maurice lists all four officinae for Constantine I and officina S (bust type B4) for Licinius I. See: J. Maurice, Numismatique constantinienne, vol. I, Paris 1908, p. 215; one example on plate XVIII, no. 4.
Voetter lists only officina S for Licinius I (Voetter, p. 229, no. 30) but gives laureate head r. as bust type!
Kent follows Cohen in listing LIBERATOR ORBIS type for both Augusti, Constantine and Licinius, but he identifies it as minted exclusively at Rome in 312-313 (see Kent, p. 50, no. 454-455).
Type is listed also in RBC (only for Constantine I, no. 234CI, p. 31 and plate 14) and in: Meixner, I., "Neki kovovi iz nalaza kod Stoca koje ne poznaje najnovija radnja Sutherlanda »Roman Imperial Coinage«, VI sv. 1967. godine" [Some coins from Stoca hoard which are unlisted in the latest Sutherland's work "Roman Imperial Coinage" vol. VI, 1967], Numizmatičke vijesti, vol. XVI/27, 1969, p. 16-18 and plate V (only for Licinius).
Finally, Doyen has attested four officinae for Constantine I (bust B4) and three officinae for Licinius I (S, T, Q; bust type B5) (see: Jean-Marc Doyen, "Une émission constantinienne méconnue (Rome, 313) et la date de la 3ème réduction pondérale du follis", Bulletin du Cercle d'Études Numismatiques 1990, no. 1, pp. 1-9).
Note that there are two minor variants of reverse: with or without shield on left arm. Emperor is probably always laureate (Cohen gives "Licinius casqué" for no. 132). He has right hand raised and empty, but, surprisingly, on some specimens tip of spear is visible near the lion's head.
Coin should be listed after ROME 17.
ROME [after 17], CONSTANTINE I, UNLISTED ISSUE, OFFICINA P
ROME [after 17], CONSTANTINE I, UNLISTED ISSUE, OFFICINA S
ROME [after 17], CONSTANTINE I, UNLISTED ISSUE, OFFICINA Q
ROME [after 17], LICINIUS I, UNLISTED ISSUE, BUST TYPE B4, OFFICINA T
ROME [after 17], LICINIUS I, UNLISTED ISSUE, BUST TYPE B5, OFFICINA P
ROME [after 17], LICINIUS I, UNLISTED ISSUE, BUST TYPE B5, OFFICINA S
ROME [after 17], LICINIUS I, UNLISTED ISSUE, BUST TYPE B5, OFFICINA T
ROME [after 17], LICINIUS I, UNLISTED ISSUE, BUST TYPE B5, OFFICINA Q
ROME [after 17], LICINIUS I, UNLISTED ISSUE, BUST TYPE B5