The witnesses at their wedding:
* Civil wedding
for Filip: archduke Simeon of Austria, prince Henri of Luxemburg
for Mathilde: countess Elisabeth d'udekem d'Acoz, baronnes Stephanie de
Radiguès de Chennevière.
* Church wedding
prince Laurent of Belgium, count Charles-Henri d'Udekem d'Acoz, Christiaen Alting von Geusau, prince Nikolaus of Liechtenstein, princess Astrid of Belgium, countess Hélène d'Udekem d'Acoz, Agnès du Parc, princess Hélène von Bayern.