On 15 October 1988, frantic preparations were under way in Madrid for a state visit by Queen Elizabeth II and Prince Philip, the first ever made by a British monarch to the country.
That day the then Prince Felipe had been handing out the Prince of Asturias awards, but one of his prizewinners, the Duke of Edinburgh, representing the World Wide Fund for Nature, would be receiving his prize in person a few days later.
The royal couple were due to arrive on the 17th, and would stay for five days, which the Spanish media proclaimed proudly would be the longest visit the Queen had made to any country outside the Commonwealth.
For the Spanish royal family this visit was extremely important for two reasons: firstly because it was historic and secondly because it was a public sign of a thawing in the official relationship between the Queen and King Juan Carlos, who are cousins.
They had had a warm relationship in private, but in terms of public relations things had cooled considerably when the Spanish monarch refused to attend the wedding of Prince Charles and Lady Diana Spencer because the couple would be setting off from Gibraltar on their honeymoon cruise.
Juan Carlos had reportedly rung 'Lilibet', as he and other relatives call her, to ask her to persuade them to change the arrangements, but with no success.
The Spanish monarchs had made a State visit to the UK in 1986, but this return visit was the icing on the cake for Spanish diplomacy.
The visit was, by any standards, a glittering success. In fact, as a taster, on 15 October during the Prince of Asturias Award ceremonyPrince Felipe announced that the Duke of Edinburgh was to be presented with an award as president of the World Wildlife Fund during his stay.
The royal couple, who stayed at El Pardo, attended a State Banquet, addressed the Spanish parliament, visited El Prado museum and El Escorial and attended a key-giving ceremony. King Juan Carlos and Queen Sofia accompanied the British couple to Seville and Barclona, where they held a reception for 300 people on board the royal yacht Britannia. The Queen and Prince Philip then sailed to Mallorca to spend an off-duty weekend with their Spanish cousins before flying back to the UK.