Antoninianus - Probus Nude, left, spear and square shield [Aegis]; FIDES MILIT; Fides

Reverse

Fides, draped, standing left, holding ensign in each hand.
Officina, value mark (XX) and mintmark in exergue.

Script: Latin

Lettering: FIDES MILIT

Unabridged legend: Fides Militum.

Translation: Loyalty of the soldiers.

Comment

RIC 364 was minted by the 6th officina (exergue/officina mark: VIXXT) of the Ticinum mint (VIXXT). The XX stands for 20 parts alloy (instead of the more usual XXI for a copper to silver ratio of 20:1). The original RIC text mentions 4 different variations/different bust types and multiple variants are published (bust types according to Pierre Bastiens grouping of bust types; see illustrated: probvs.net):

1. Radiate, draped and cuirassed, right (A2 bust, example probuscoins #324, Numista #292712);
2. Radiate, cuirassed, right (B bust, example probuscoins #345, Numista #293481);
3. Radiate, wearing imperial mantle, left, holding sceptre surmounted by eagle in right hand (bust H2 (*), example probuscoins #333, Numista #293482);
4. Radiate, wearing imperial mantle, left, holding spear, seen from back ((*) busts listed by RIC, and other sources, but unverified; see: probvs.net on busts, at the bottom, not in Numista);
5. [var] Radiate, heroically nude, left, holding spear in right hand and square shield (aegis) in left hand, from behind (bust F19, no example on probuscoins, Numista #419814);
6. [var] Radiate, cuirassed, left (B1 bust, example probuscoins #984, Not in Numista);
7. [var] Radiate, cuirassed, left, holding spear in right hand and shield in left hand, from behind (F8 bust, example probuscoins #2434, Not in Numista);
8. [var] Radiate, cuirassed, left, holding spear in right hand (F5 bust, example probuscoins #4633, Not in Numista).

(*) OCRE mistakenly does not list the H2 bust but only the unverified fourth bust.

According to Pink, RIC 364 - with its obverse lettering nr. 2 ('IMP C M AVR PROBVS AVG') combined with 'Hauptrev: FIDES MILIT' (st. l), - is part of the 2nd emission (the year 276) and 3rd emission (277) (Karl Pink, Der Aufbau der römischen Münzprägung in der Kaiserzeit VI/I, Wien, 1949, p. 60-61). According to Pink, the 6th officina used 'FIDES MILIT' (st. l)', in the 3rd emission exclusively with the H2 bust (see Pink: "AZ" for "Adlerzepter" or 'eagle sceptre'). Both probuscoins.fr as probvs.net attribute the A2 bust of RIC 364 to the 2nd emission and the other busts, including the variant busts (the F19 bust variant is not listed), to the 3rd emission.

The F19 bust variant was most likely part of the 4th emission (year 278), because all known examples of F19 bust used in Ticinum are of the 4th and 6th emission. This does not fit into Pink's schematics but is supported by the fact that, during the 4th emission Probus' victory over the German tribes was celebrated, which resulted in all kinds of special obversus, reverses and legends, including the introduction of heroic busts. About Probus' Germanic campaign and its effects on the Ticinum mint, see also: S. Estiot, Une campagne germanique de l'empereur Probus: l'atelier de Ticinum en 277-278, Droz p. 207-247, 2006.

Interesting fact