★ Fascinating overstrike ★

Constantine X and Eudocia (1059-1067) AE follis. Constantinople, 8.88g, 31.5mm.
Obv: + EMMA-NOVHΛ - Christ standing facing on footstool, wearing nimbus and holding Gospels, IC XC across fields
Rev: EVΔKAΥΓU +KWNTAK - Eudocia on left, wearing loros with kite-shaped lower panel and crown with cross and pendilia, Constantine on right, wearing loros and crown with cross and pendilia, both standing facing, holding labarum with cross-piece on shaft between them, standing on base and three steps, each places one hand on heart.
DOC 8; Sear 1853
Overstruck on Class C anonymous follis, attributed to Michael IV (1034-1041), SB 1825.
From the Severus Alexander collection.

Remarkably, the reverse of this coin looks to be the Constantine X coin (SB 1853) overstruck on the anonymous follis (SB 1825) - but given the currently accepted dating of the anonymous issue, this should be impossible! As Sherlock Holmes said, “Once you eliminate the impossible, whatever remains, no matter how improbable, must be the truth.” Here, then, is the improbable explanation: the reverse was struck twice, above and below the horizontal bar of the cross, creating the illusion that SB 1853 is the undertype. First only the bottom of Constantine and Eudocia’s robes were struck up, leaving the crossbar unaffected. Then the mint worker compensated for the mistake by again striking the coin at an oblique angle, impressing only the head and shoulders portion of the Imperial couple, and still leaving the crossbar alone - and completing the illusion. (Meanwhile the two obverses practically coincide, so the overstrike is not obvious there.) A remarkable error coin!