Constantine II, as Caesar, 316-337. Follis (Bronze, 20 mm, 3.26 g, 6 h), Rome, 317. CONSTANTINVS IVN NOB CAES Bare-headed, draped and cuirassed bust of Constantine II to right, seen from behind. Rev. PRINCIPIA IV-VENTVTIS / A / R T Mars standing front, head to left, placing his right hand on shield set on ground and holding inverted spear in his left. RIC 94. Of the highest rarity, apparently the second known example. Somewhat smoothed and with traces of corrosion, otherwise, good fine.