I originally bought this coin, a demi-teston of Henri II to add to my French collection. The countermark however has given me great fun. Fairly obviously it is the swimming lion of Zeeland, but there my investigations stalled. A while ago I found an online article saying the countermark is from 1573/4 and applied to coins to make them legal tender. A 15% tax was levied, and this used to help fund the war effort against Spain. Several different countermarks were used, and applied to the King's neck. Countermarked 'foreign' coins are unusual. Coin Talk are an erudite bunch of folks, so any further information would be greatfully received.
Countermarks on gold are rare and very $$$$$ but for those of us who labour in the lesser fields of silver and copper, they are quite common and not necessarily expensive. As John Scholefield says, in 1573 the Zeeland rebel government (like Holland) counterstamped silver coins to increase their value by 1/8, to help pay the troops fighting the Spaniards. Here is a 1570 1/2 Reichstaler of the city of Neuss with such a c/m on the rev. Holland did the same thing, using the C/M of a Holland lion in an oval (sorry - this one is a bit worn). As the leading state in the United Provinces with the largest forces, their countermarked coins are much more common than those of Zeeland. Here is one on the obv. of a 1570 Half Taler of the city of Cologne. Here is one on the obverse of a 1572 Cologne Taler.
Another coin with the Zeeland c/m on the reverse Austria Archbishopric of Salzburg Johann Jakob Khuen von Belasi 1/2 Guldentaler (30 Kreuzer) 1568
And here are some more coins with the Holland c/m Spanish Netherlands BRABANT Philip II 1/10 Daalder 1572 Spanish Netherlands HOLLAND Philip II 1/20 Daalder n.d (1562-64) In this case they countermarked a coin of their own province Archbishopric of CAMBRAI Maximilien de Berghes 1/2 Ecu 1568
Two higher denomination coins with the Holland c/m BAVARIA Albert V the Generous 60 Kreuzer 1568 with Holland c/m on breast of eagle on reverse (not too visible in the picture, I am afraid) PFALZ Friedrich III, Elector Taler 1567 with Holland c/m on helmets on reverse
