Byzantine Empire. Constans II, with Constantine IV, Heraclius, and Tiberius (641-668). AR Hexagram, Constantinople mint, 659-668 AD. Obv. Busts of Constans II, wearing plumed helmet, and Constantine IV, crowned, frontal; above, cross. Rev. Cross potent on globe above three steps between Heraclius and Tiberius, standing frontal; both crowned and holding cross-globe. MIB 152. DOC 57. Sear 998. AR. g. 5.56 mm. 22.00 About EF.