Coins of the Duchy of Courland. Numismatic items that are very popular among Polish collectors. In the offer of our upcoming auction, they will be represented by 7 spectacular trojak coins of Fryderyk and Wilhelm Kettler, and a beautifully preserved, typologically rare thaler of Piotr Biron. All presented trojak coins are examples of rarity and good condition. In such a combination, there is no doubt that these coins are doomed to success.