From imperial-russia.tumblr.com/post/134412821229/the-wonderful-court-dress-worn-by-princess-dagmar.
Dagmar is shown becoming Maria Feodorovna wearing the dress seen in this and this image.
Keywords: 1866, Zichy, Maria Feodorovna (1847-1928), Prinsesse Dagmar, Princess Dagmar, Dagmar (kejserinde af Rusland), Marie Sophie Frederikke Dagmar, Мария Фёдоровна (жена Александра III), Glucksberg family, Romanov family, Princess, Empress, Russian, chignon, floral headdress, veil, earrings, necklace, laced bodice, scoop neckline, rosettes, long Russian sleeves, cuffs, bracelets, vee waistline, full over-skirt, train