This is one of five full-length portraits of members of the Brunswick family in the Royal Collection which were first attributed to van der Doort by Oliver Millar. They are all inscribed with the date of 1609. The Princess was one of nine children and fourth daughter of Heinrich Julius, Duke of Brunswick-Lüneburg, Prince of Calenberg and Prince of Wolfenbüttel and (1564-1613) and his second wife, Elisabeth, Princess of Denmark (1573-1625), eldest daughter of King Frederick II of Denmark and Norway (1534-1588). Here the coat of arms crowned with horned helmets is that of the Wolfenbüttel family.

Dorothea wears a dress very similar to those in the other two portraits of her sisters Elisabeth and Hedwig (RCIN 404963 and RCIN 407222). Her white silk bodice is worn with a matching skirt of the same fabric which has been pinked all over to create a decorative pattern of tiny cuts. This skirt has been pinned into position so that a narrow ruffle encircles the edge of the farthingale worn beneath. She wears an elaborate lace collar which is supported on a wired rebato covered in red silk which is just visible in places. The cuffs at her wrist of a matching type of cutwork lace and she wears multiple pearl necklaces around her neck and across her body, along with a jewelled pendant broach tied with a ribbon at her breast. Her hair is piled high over pads and decorated with another ribboned jewel and pearls.

Inscribed and dated: F. DOROTHEA. / ANNO 1609