Marcian, AR 1 1/2 Solidi, Constantinople, accession issue, AD 450. 6.67 g.

DN MARCIANVS PF AVG, pearl diademed, draped, cuirassed bust right.
ADVENTVS S DN AVG, Marcian, nimbate, on horseback riding left, raising right hand.

Star in left field.
Mintmark CONOB. 

RIC X, 501; MIR B 1.
Extremely rare.

With permission of Stack's auction Jan. 2009, lot 3029.
Estimate £60-70,000