Europe's most charismatic royal? Spain gripped by 'Leonormania' as princess turns 18

In a gesture that went viral, Spain's Princess Leonor broke protocol on 12 October.

At the celebration of Spain's national day, the princess was surprised by her classmates from the military academy she had just graduated from.

As the cameras rolled, one of the cadets said to the princess: "How beautiful you look, Borbón", a compliment that brought laughter from King Felipe and Queen Letizia and a smile of complicity from Leonor.

In that natural and human moment, she could have been any teenager, but Leonor de Borbón has rarely been seen to break protocol.

From that point on, the whole of Spain has been paying more attention to the ever move of a princess destined to become the first queen of Spain in the modern era. 

On her 18th birthday on Tuesday, when she will swear allegiance to the Constitution, her popularity has soared, and Spain is gripped with 'Leonormania'. 

But the surge in her popularity has some people asking whether the princess is simply blessed with natural charm, or whether her behaviour is all part of a plan to create the perfect queen. 

With her innocent face, blue eyes and permanent smile, Princess Leonor has managed to win over the Spanish people.

She has even succeeded in renewing the image of the royal house and silencing some of the voices critical of the actions of her controversial grandfather, former King Juan Carlos.

The retired king's elephant hunting expedition, his secret stache of cash in Switzerland, and the harassment lawsuit filed by his former lover Corinna Larsen caused his popularity to plummet, dragging the crown down with it.

However, Leonor has been able to reconcile the Spanish with the Crown.

While it's difficult to know the level of support for the princess, as the Spanish Sociological