Prince Felipe and Princess Letizia were at the opera at the Gran Teatre del Liceu in Barcelona, where republican sentiment can often run deep.
Newspaper El Mundo posted a video, which shows how strong people can feel for an against the Spanish Royal Family.
People shouldn’t be surprised, however. During the transition to Democracy, King Juan Carlos and Queen Sofia were often greeted with jeers and screams, especially in places like Catalonia and the Basque Country.
In recent days King Juan Carlos has met with Austrian Chancellor Werner Feymann and Guatemalan President José Mujica.