For more Edwardian Costumes see House of Worth Couture
Evening dress, ca. 1905-1910. This dress is in the collection of the National Museum of Art, Architecture and Design in Oslo, where Queen Maud of Norway's clothing and belongings are housed. While the museum site does not mention this dress being worn by her, I have a strong suspicion that it might have been hers. I also once saw a photo of an exhibition of Queen Maud's clothing and this dress was shown in the background.