Infanta Sofía's First Communion: A low-key class affair in school uniform like her sister's

In both cases, the girls' confirmation was a joint event with their classmates at their school, the Santa María de los Rosales in Madrid, in the Our Lady of the Assumption (Nuestra Señora de la Asunción) parish church in the city's Aravaca district.

On both occasions, the sisters wore their school uniforms instead of a flamboyant white dress resembling a wedding gown, which would normally cost several hundred or even thousand euros.

The service, and later party, were private family affairs with only the relatives of the youngsters taking their First Communion invited.

In the case of Sofía, who turned 10 years old a fortnight ago, both sets of grandparents – the retired King Juan Carlos I and Queen Sofía, whom she was named after, and HRH Letizia's parents Paloma Rocasolano and Jesús Ortiz – as well as her great-grandmother, Letizia's grandma Menchú del Valle, and the Infanta Sofía's godfather, Prince Konstantin of Bulgaria, son of the eastern European country's King Simeon.

Reporters were not allowed to view the ceremony, which was a low-key, close-knit affair, but members of the family greeted them at the entrance and on leaving.

Sofía did not speak, but smiled widely and nodded when asked if she was 'happy' to be going through her First Communion.

Her elder sister Leonor, 11, wore a simple powder-blue dress with matching ballet-pump-style shoes.

When Leonor was confirmed, the King and Queen made the decision to hold a more demure ceremony, in school uniform and among classmates, without the pomp and circumstance that most children bask in during their first Holy Communion and which has normally been multiplied for Royals.

In the same way as King Felipe's coronation was a discreet affair with no street pageants or crowns, the Royal family decided it would not be proper to make a show of wealth and luxury when Spain continues to fight back from its worst recession in a century.