English: Poltred Frederig IX Brandenburg (1588-1611), mab of John George, Elector of Brandenburg.
"This is one of a series of nine miniatures painted in oil on eight pieces of card (420463-420470) representing John George, Elector of Brandenburg, two of his three wives and six of his children by his third wife, Elizabeth. The paraph at the end of the inscription in each case has been interpreted as a punctuation mark rather than a monogram and the group remains unattributed. The hand is, however, the same as that of the miniaturist who painted a large number of similar miniatures formerly in the Herzoglisches Museum, Gotha (current location unknown). The Herzoglisches group were distinguished by the same prefix 'V.G.G.' before the inscription describing the sitter in each case. The miniaturist is believed to have been working at the court of John George, Elector of Brandenburg, c. 1593. The group were not part of the Hanoverian additions to the Royal Collection, but were acquired in the nineteenth century, from a dealer in antique linens who travelled extensively in Europe and found them hidden in some of his merchandise, ostensibly secreted there during the French Revolution. Frederick, sixth son of John George, Elector of Brandenburg and his third wife, Elizabeth. Inscribed at the top in gold: V.G.G. FREDERICH MARGGRAFF ZU BRANDENBURG." [1]