Septimius (Roman emperor usurper)
Septimius or Septiminus was a Roman usurper proclaimed emperor in 271, in Dalmatia, during Aurelian's reign. His revolt soon petered out, when the menace of a Gothic invasion faded out, and Septimius was killed by his own troops.
References
S.v. "Aurelian", De Imperatoribus Romanis site