Alexander III, AR tetradrachm posthumous issue, Babylon  mint. Struck by Seleukos I Nikator, ca 311-305 BC. 26 mm, 16.81 g. 

Head of Herakles right, wearing lionskin headdress.
BASILEWS ALEXANDROY, Zeus seated left, right leg drawn back, holding eagle and sceptre.
MI in left field. MTR monogram in wreath beneath chair, countermark of sun-like symbol with 16 rays.

Price 3751; Mueller 735; Armenak hoard 138-139.

With permission of Numismatik Lanz, auction 121, Lot 183, Nov. 2004