Wikipedia
Felicissimus (died 271?) was a public officer in Ancient Rome, during the reign of Emperor Aurelian. He is famous because he led an uprising of mint workers against the Emperor, but was defeated and killed, possibly in 274, but more probably in 271.
Felicissimus was a rationalis, the chief of the state treasury. One of the responsibilities of the rationalis was to administer the imperial mints. The workers of the mint in Rome had been engaged in adulterating the coinage and Felicissimus was held responsible and executed. An uprising of the mint workers followed; it is reported that 7,000 soldiers were killed during this revolt (Aurelius Victor xxxv 6; Historia Augusta, Aurelianus, xxxviii 2-4), although it would not be surprising if this were an exaggeration. It is possible that this uprising was somehow connected with the senatorial and equestrian classes, as Aurelian executed several senators.
The fact that the mint of Rome was inactive for a short time before the monetary reform of 274 could be a consequence of this revolt, and the poor quality of the coinage at the beginning of Aurelian's reign supports the suggestion that the workers at the mint were adulterating the coinage.