John and Cornelius de Witt (1625 and 1623 to 1672) were distinguished statesmen in Holland with extraordinary diplomatic prowess. They brokered several significant international agreements and generally kept England and France at bay for many years. However when Louis XIV of France suddenly declared war and overran Holland, the Dutch people turned to William III of Orange for leadership. The de Witt brothers opposed William III, leading to violent demonstrations against them and eventually their death at the hands of an angry mob. Their mangled remains were hung by the feet from a lamp-post.
There are several medals which commemorate the De Witt brothers. The one in our primary picture (thanks to ha.com) is the most common and sells retail for these approximate prices:
WHITE METAL: worn: $50 US dollars, uncirculated: $100
SILVER: worn: $100, uncirculated: $400
Expect dealers to buy these pieces at about one-half retail value.
Our secondary picture shows a large silver medal with the brothers facing each other. It is worth significantly more than the common variety, and a gold version of it tips the value scales.