Gallienus (253-268 AD). AV Aureus (19-20 mm, 1.97 g), Milan. Sole reign.

Obv. GALLIENVS AVG, radiate head right.
Rev. ORIENS AVG, Sol standing left, holding whip and raising right hand.
Officina letter P in exergue.

RIC 448; Cohen 683; Sear 10090.

Very rare. 

With permission of auctiones.ch, eAuction #42, Lot 81. 
Estimate: CHF 1'200.00