Extremely rare denarius, in the Frynas catalog with the highest degree of rarity - ER (EXTREMALY RARE).
Coin minted in Mazovia by Boleslaw, son of Conrad of Mazovia.
Probably the only known coin type of this Ruler.
A very nice piece, despite slight chipping.
For the best collections - definitely recommended.
obverse: head with hair to the left, double border, BOZALVAS EL inscription in the rim.
reverse: probably the same as the obverse (description from J.Frynas' publication)
Silver, diameter 14.5 mm, weight 0.08 g.