This is the 1513 Poland War Horse / Knight on Horseback 1/2 Groschen Antique Medieval Silver Coin. 

This unique silver coin features a powerful image of a knight on horseback from the 1513 Polish-Lithuanian War. The coin has been circulated and is ungraded, but its historical significance and stunning design make it a must-have for any serious coin collector. Made in Poland and featuring the country's coat of arms, this coin is a testament to the rich history and tradition of the region. It is a great addition to any collection of world coins and a fascinating piece of history that will surely spark conversations.