Fashion fans and royal followers will be able to get a closeup look at the dress that Diana, Princess of Wales, wore on her wedding day in 1981. The gown, with its 25ft sequin-encrusted train that dramatically filled the aisle of St Paul’s Cathedral, will be on show for the first time at Kensington Palace in 25 years. Diana’s children, the Dukes of Cambridge and Sussex, have loaned the gown to the London exhibition, Royal Style in the Making, which opens to the public on 3 June and continues to the new year. The temporary exhibition looks at what it is like to design an outfit for a royal client. The dress that Diana wore when she married “is now among the most famous in bridal history”, organisers say. It features a fitted bodice overlaid at the centre both front and back with panels of antique Carrickmacross lace that had originally belonged to Queen Mary. It also has a scooped neckline and large puffed sleeves that are trimmed with bows and deep ruffles of taffeta – a style made popular by Diana in the early 80s. Its designers, David and Elizabeth Emanuel, also crafted a full skirt for the dress that is supported on a mountain of stiff net petticoats. A rare surviving toile for the 1937 coronation gown of Queen Elizabeth, the Queen Mother, consort of King George VI, is among the other items of royal fashion history that are going on display. Original sketches, fabric swatches and unseen photographs from the royal ceremonial dress collection will also be on show. An array of glittering gowns and stylish tailoring created for three generations of royal women is also billed to be among the items going on display at the Kensington Palace Orangery.