Leo I, AE4, 457-474 AD. Possibly Alexandria.

Obv: D N LEO[NS P F AVG], pearl diademed, draped, cuirassed bust right.
Rev: Leo's Latin type monogram within wreath. 
Vagi 3793; RIC X 694

Courtesy of forumancientcoins.com, Nov. 2010.
  	  	
RIC_0694