KINGS OF THRACE. Lysimachos, 305-281 BC. Tetradrachm (Silver, 35 mm, 13.88 g, 1 h), Byzantion, circa 80-75 BC. Diademed head of Alexander the Great to right with horn of Ammon over his ear; behind, countermark: CL•CAES within rectangular incuse. Rev. ΒΑΣΙΛΕΩΣ - ΛΥΣΙΜΑΧΟΥ Athena seated left, holding Nike, crowning the king's name, in her right hand and leaning with her left arm on shield decorated with gorgoneion; behind, transverse spear; in inner left field, monogram; on throne, BY; below, ornamented trident. Callataÿ Group 4, p. 127. Müller -, cf. 216-217. Very rare with this interesting countermark. Patchy toning, otherwise, very fine.
The countermark was applied under Claudius (41-54), perhaps to revalue the coin as a cistophorus