He was also a master of diplomacy and for 10 years he served as an ambassador of the Swedish queen Christina. In this capacity de Groot played a key role in the negotiations between Sweden and France in the aftermath of the Thirty Years’ War.
Although he died in 1645, his influence continued well into the following century, as can be seen by the fact that almost 150 years later he was honoured by a portrait on this 6in (16cm) high wine glass, which is coming up for sale at Dr Fischer in Heilbronn on March 20 with a guide of €40,000-60,000.
The decoration, which is signed and dated 1785, was the work of David Wolff, considered to be one of the great masters of 18th century Dutch stipple engraved glass. His portrait of de Groot can be traced back to a 1631 oil painting by Michiel Jansz van Miereveld, which was reproduced in an engraving by Willem Jacobsz Delff in the following year.
The glass itself has an interesting pedigree: from the late 19th century at the latest, it belonged to the extensive collections of the margraves and archdukes of Baden which were dispersed by Sotheby’s in 1995.
It was later owned by the German collector Wolf-Horst Röhl, whose legacy has provided many interesting pieces for the auction house in Heilbronn.