For the pre-wedding gala dinner for her son, then-Prince Felipe to Letizia Ortiz Rocasolano, Queen Sofia wore a gold and cream gown by Spanish fashion designer Manuel Pertegaz (who designed her soon-to-be daughter-in-law's wedding gown). 

King Juan Carlos and Queen Sofia hosted the pre-wedding dinner for their son and his fiancé where 350 guests attended including many of the royals who were invited to the wedding. These include the Prince of Wales, King Constantine and Queen Anne-Marie of Greece (Felipe’s maternal aunt and uncle), then-Queen Beatrix, then-Prince Willem-Alexander and Princess Máxima of the Netherlands and members of the exiled Iranian Royal Family.

Of course, the full Greek Royal Family attended, as Sofia was previously a Princess of Greece and Denmark; her older brother is the deposed King of Greece.

Guests dined at candle lit tables with orange tablecloths. 

The gala dinner was held on May 21, 2004, at the El Pardo Royal Palace in Spain's capital of Madrid. Felipe and Letizia married in a Roman Catholic ceremony the next day in the city at the  Cathedral Santa María la Real de la Almudena. The wedding was dedicated to the victims of the Madrid terror bombings in March of that year. 

More on their wedding can be read here.