Isaac II Angelus, first reign, 1185-1195. Aspron Trachy (Electrum, 30 mm, 4.61 g, 6 h), Constantinople. (MHP) - XC (sic!) The Virgin Mary enthroned facing on straight-backed throne, nimbate, wearing pallium and maphorium, holding before her the nimbate head of the infant Christ. Rev. [ICAAKIOC ΔEC O] Isaac II, on left, standing facing, wearing divitision and chlamys, holding cruciform scepter in right hand and akakia in left, being crowned by the Archangel Michael who stands beside him on right, wearing military attire and holding jewelled scepter in his left hand; in field to lower right, X / M. Cf. DOC 2b and SB 2002. Extremely rare, if not unique with this die engraver's error. Clear and attractive. Usual striking faults, otherwise, nearly extremely fine.
This engraver's error, with the expected ΘV of the Virgin replaced by Christ's XC, has not been duplicated by any published example known to us, including those on Coin Archives and AC Search.