Constans. As Caesar, AD 333-337. Æ Follis (16mm, 1.91 g, 6h). Arelate (Arles) mint, 1st or 2nd officina. Struck AD 336. Laureate, draped, and cuirassed bust right / Two soldiers standing facing one another, each holding reversed spear and resting hand upon shield; between, signum surmounted by banner with Christogram; [P or S]CONST. RIC VII 397; Ferrando 1194-5. Brown patina. EF.
Ex 1989 Nether Compton (Dorset) Hoard.
The Christogram is a monogram of the Greek letters chi and rho which begin the name of Christ. It appears as early as AD 315 on coins of Constantine I. By AD 327 it appears on the banner of a labarum from the Constantinople mint. It is clear that by that date the Christogram had become a symbol of military success.