King Juan Carlos was obliged to visit Malta alone after Queen Sofia was “indisposed”, it was announced just hours before the royal couple was due to land in Malta.

At first it was thought the queen had been stricken by an unknown illness, though Madrid palace staff have been quick to stress she is not suffering from swine flu.

But some hours later it was announced that the real reason may well have been the fact that the queen’s eldest daughter had signed divorce papers the night before.

The Infanta Elena de Borbon, eldest daughter of Spain’s King Juan Carlos and Queen Sofia, and Jaime de Marichalar formally ended 14 years of matrimony. Officially known as the Duke and Duchess of Lugo, the couple separated two years ago. Marichalar has been stripped of his title of “Duke of Lugo”.

According to a release distributed by the couples’ lawyers – and not the royal house – the Infanta will maintain custody of the couples’ two children, Felipe and Victoria. Marichalar will provide his children with a monthly allowance.

Given the royal family’s ties to the Catholic Church, the couple will seek an annulment of their marriage directly from the Vatican. They married at the cathedral in Seville in 1995 and thousands gathered to watch the couple marry.

Their romance began after the pair met in Paris in 1987, where Elena was studying French literature and Jaime was working in a bank.

Theirs was the first royal wedding in Spain since 1906. King Juan Carlos and Queen Sofia married in exile in Athens during the Franco dictatorship.

It is not known how quickly – or whether – Pope Benedict XVI will grant an annulment. It took 12 years for Pope John Paul II to annul the marriage of Princess Caroline of Monaco to Parisian banker Philippe Junot.

When the couple initially separated, it was announced that the separation would be temporary, but as time went on it became clear that a divorce was inevitable.