I just got this "mule" or hybrid. Diocletian A.D. 300- 301 28mm 11.4g IMP C DIOCLETIANVS P F AVG; laureate head right. SACRA MON VRB AVGG ET CAESS N N; Moneta standing left with scales & cornucopiae. In ex. Q thunderbolt cf. RIC VI Rome 100a This coin from Rome has a mintmark of Q thunderbolt; but the Rome mint at this time, according to Roman Imperial Coinage VI, assigned mints on seniority— First Tetrarchy workshop assignment at Rome Prima (1st) Diocletian Secunda (2nd) Maximianus Tertia (3rd) Constantius I Quarta (4th) Galerius In the footnotes, RIC notes a coin of Maximianus with T; when it should be S (for secunda), and calls it a "hybrid ?" So, apparently, a mint employee accidentally paired a reverse for Galerius with an obverse of Diocletian; which resulted in this hybrid or mule. Also interesting is the thunderbolt in the mintmark. Diocletian claimed descent from Jupiter, so a thunderbolt was used to remind everyone of his godly lineage. Maximianus was descended from Hercules, so this series also used a club. Maximianus A.D. 300- 301 Ӕ follis 28mm 6.9gm IMP C MAXIMIANVS P F AVG; laureate head right. SACRA MON VRB AVGG ET CAESS NN, Moneta standing left with scales & cornucopiae. In ex. S club RIC VI Rome 100b The reverse legend SAC MON VRB AVGG ET CAESS NN (and all the variations) roughly translates as "The sacred money of the city of our rulers" This type was struck around the same time as the Edict on Maximum Prices issued by Diocletian in A.D. 301 and this sacred money coin may have been a reference to this edict (RIC gives dates of 300-301 for the coinage; but this was a short series possibly only struck in 301). This attempt to regulate inflation was (surprise) a failure though.
