Does anyone know what kind of uniform is the groom wearing?...
I'm going to answer my own question...
I've read that he was wearing the uniform of a Knight Commander of St Sylvester, he was awarded with back in 2004, by Pope John Paul II.
The other insignia are knighthood awards from the Duke of Bragança (the top star) and from the Portuguese President (the bottom star).
The bride's gown was designed by Valentino and she complemented it with a family tiara.
Mr. Bailey is an interfaith campaigner, so the wedding was concelebrated by a series of senior ecumenical leaders.
According to different media, the bride's witnesses were Princess Marie-Christine von Hohenberg, Countess Henriette du Bessey de Contenson, Baron Alexander Dóczy, Countess Fleur von Goess (née Duchess von Württemberg) and Mrs. Livia Engel.
From the groom, the witnesses were Baroness Scotland of Asthal, Prince Konstantin-Assen of Bulgaria, Dr Alberto Laplaine Guimarães (a Portuguese lawyer and professor), Mr Peter Jonas and Lord Nicholas Windsor.