Diana Álvares Pereira de Melo, 11th Duchess of Cadaval

In the summer of 2015, the duchess collaborated with Hubert de Givenchy to open to the public an exhibit of haute couture bridal gowns in the palace church, Saint John-the-Evangelist.

Chosen and arranged by Givenchy, the twelve dresses on display were originals borrowed from such designers as Yves Saint-Laurent, Balenciaga, Dior and include "The Nun" gown designed in 1972 for the marriage of the Spanish Caudillo Franco's granddaughter, Carmen Martínez-Bordiú to Alphonso XIII's grandson Alfonso de Bourbon, Duke of Cadíz, as well as the Givenchy dress Diana wore for her own 2008 wedding.

Dom Duarte Pio, Duke of Braganza recognized Diana as 11th Duchess of Cadaval (on a non-hereditary basis, as all holders of the Dukedom of Cadaval in the past have obtained royal recognition of the title during their lifetime), acting on the authority attributed to him post-monarchy by the Conselho de Nobreza (Council of the Nobility) as Head of the Royal House of Braganza.

On 21 June 2008, Dona Diana married Prince Charles Philippe d'Orléans, (born 1973), a grandson of the Orleanist pretender Henri, Count of Paris.

Both wife and husband are Capetians, descending in unbroken male line from King Robert II of France (972–1031), Diana from his younger son Robert I, Duke of Burgundy through the royal (though illegitimate) Portuguese branch of the House of Braganza, and Charles-Philippe through the elder son, King Henry I of France, via the cadet branch of the House of Bourbon-Orléans.