The couple were married on 2 May 2004 in the Almudena Cathedral at the Royal Palace of Madrid.
Their engagement was announced by the royal household on 1 November 2003 – and it came as a big surprise to many.
Letizia and Felipe announced their engagement in 2003
The couple had managed to keep their romance out of the spotlight – despite the fact that Letizia was already a household name.
The future queen had worked for a number of years as a journalist on news channels including 24 Horas, Telediario 2, the most viewed newscast in Spain.
The future queen worked as a newsreader
In 2000, she reported from Washington DC on the presidential elections; in 2001 she broadcast live from Ground Zero following the 9/11 attacks; and in 2003 she filed reports from Iraq following the war.
The couple were married in 2004
Letizia also stood out as a divorcee. In August 1998, she tied the knot with Alonso Guerrero Perez, a writer and high school literature teacher, in a simple civil ceremony after ten years together. It didn't last and just one year later, in 1999, they were divorced.
Felipe and Letizia with their daughters
It's been a big week for the Spanish royals. On 30 January, King Felipe celebrated his 55th birthday – and his family no doubt pulled out all the stops to make it special.
Just a few days earlier, Queen Letizia made headlines when an Iranian ambassador failed to shake her hand. You can watch her reaction in this video...
Felipe is the third child and only son of former King Juan Carlos and Queen Sofia and inherited the throne ahead of his two older sister, Infanta Elena and Infanta Cristina.
LISTEN: KING CHARLES: THE MAN BEHIND THE CROWN
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