Friedrich Brentel, from Strasbourg, here displays his detailed skill in watercolour technique which derived from the Flemish tradition of manuscript illumination and was applied elsewhere in his work to subjects such as small-scale religious scenes. Brentel's subject, George, Duke of Brunswick-Lüneburg-Kalenberg, was the sixth son of William the Younger, Duke of Brunswick-Lüneburg, and became Duke of Kalenburg in 1636 and was was the grandfather of George I of England. He is shown here booted and spurred with his sword at his side, as the embodiment of authority; his wife's miniature (420625) completes the pair. Signed indistinctly on the gold border, bottom left: Brentel and incribed, probably by the artist, on paper laid on the backboard: F. Brentell a: 1630.