Charles III de Croÿ was Seigneur de Croÿ, 4th Duke of Aarschot, 5th Prince of Chimay and 5th Count of Beaumont. He played an important role on both sides of the Dutch Revolt. He was an avid collector of art and coins. His favourite residences were the Château de Beaumont and Heverlee castle, where he housed his collections and created beautiful gardens.

Jacob de Bie, known in France also as Jacques de Bie was a Flemish engraver, publisher and numismatist who worked in Antwerp, Brussels, Paris and Arnhem. As a reproductive artist he made engravings after designs of other artists of his generation. He was engaged in numismatic collecting and categorisation and was an official at the mint in Brussels. He is now mainly known for his publication of portraits of French kings.