Weekly Trivia: Constantine the Great was the first Roman emperor to feature the Chi-Rho (Christogram) on imperial currency. The symbol first appeared subtly on a silver medallion in 315 AD and was later used prominently on the "Spes Publica" bronze coinage (c. 327 AD), marking the beginning of the Empire's visual transition to Christianity.
Sources: Eusebius of Caesarea, Life of Constantine (Vita Constantini), Book I, Chapter 31. | Wikipedia
