Carla Bruni meets her match in Princess Letizia

The Spanish press called it a "a duel of elegance and glamour" - the moment Carla Bruni finally came face to face on a state visit with a woman whose beauty threatened to outshine her own, Princess Letizia, the wife of Crown Prince Felipe, heir to the Spanish throne.

Carla wore violet, Letizia wore raspberry, and the air-kissing alert was high for lunch on the first day of the Sarkozys' visit to Madrid.

The day began when the French President and his wife were greeted by King Juan Carlos and Queen Sofia at the Prado Palace outside Madrid. Carla Bruni, sporting a new hair-do, wore a black dress with white bolero style top.

The assembled snappers were shocked to see Bruni kiss the Queen on both cheeks rather than curtsying, but a spokesman for the royal family explained diplomatically that a curtsy before a Spanish monarch "is not an absolute obligation, but a habit adopted by some people".

By lunchtime, Bruni had changed into her violet number for the meeting with Letizia, a former journalist and news presenter who covered the 9/11 attacks and the Iraq war for Spanish television

Today the trip gets more serious - and potentially more awkward - when President Sarkozy attends a summit with Spanish Prime Minister Jose Luis Rodriguez Zapatero. Officials in Paris and Madrid have tried to play down any tension caused by Sarkozy's alleged comment two weeks ago that Zapatero was "not very smart".

Both sides are concentrating instead on the level of cooperation between the French and Spanish in their efforts to arrest leaders of the Basque separatist group Eta, and in their drive against organised crime and drug trafficking.

Bruni's date for lunch will be another powerful Spanish woman, Zapatero's opera-singing wife Sonsoles Espinsa.

Meanwhile, Bruni may have a slight embarrassment to deal with back home in Paris. According to reports, a computer containing photos of the French First Lady has been stolen from the Paris apartment of her former lover's younger brother.

Bruni and Raphael Enthoven, a philosophy professor, had a child, Aurelien, before separating. The nature of the missing photos is unclear though the Sun newspaper reports today that they are "intimate".