A very nice, finely struck piece of gold coinage of the first electoral king of Poland.
Rarer third ecu d'or type of this ruler with a religious legend on the side of the cross.
Obverse: crowned coat of arms of France, in the rim the legend:
HENRICVS-III-D:G-FRAN-ET-POL-REX-1578-K;
Reverse: stylized cross, in the rim legend:
+CHRISTVS-REGNAT-VINCIT-ET-IMPERAT;
Gold, diameter 22.5 x 23.5 mm, weight 3.27 g.