Diocletian and Maximianus, Billon Octadrachm, Alexandria, AD 298. 7.71 g.

DIOCLETIA–ANVS AVG, radiate head right.
MAXIMI–ANVS AVG, radiate head right. 

RIC V-II, 338; Dattari (Savio), pl. 282, 10625 (this coin); Cohen 8; Sear 12970 (attributing the coin to Siscia). 

Extremely rare.

With permission of Hess-Divo AG, Auction 324, Lot 76, Oct 2013