British and Spanish officials agree it is high time for old quarrels between the two European nations to be forgotten. The three-day visit by King Juan Carlos and Queen Sofia, which began Tuesday, is intended to help in this process. There is much admiration here for the Spanish King's defense of democracy and his determination to see Spain's Fascist past buried. But an unsettled territorial dispute, focusing on the tiny British colony Gibraltar, could hamper efforts to achieve lasting improvements in relations.
It is believed that King Juan Carlos will take the opportunity during his visit to underline Spain's claim to sovereignty over Gibraltar -- whose inhabitants insist that they are British subjects.
If he does, the British government is just as certain to make it clear that until there is a negotiated solution to the problem of Gibraltar, the ``Rock,'' as it is affectionately called by Britons, will remain under London's control.
The royal visit, coming less than four months after Spain's entry, along with its neighbor Portugal, into the European Community, has been meticulously planned as an exercise in interstate relations. It is the first state visit by a Spanish monarch to Britain since 1905, and only the second since the 16th century.
Britain is anxious that Spain remain on the democratic road, and that its membership in the EC and NATO continue. To show its seriousness on these matters, the government of British Prime Minister Margaret Thatcher has arranged for the Spanish King to address a joint session of Parliament -- a rare honor for a visiting head of state, let alone a monarch.
Historically, Roman Catholic Spain and Protestant Britain have been enemies. Both had huge overseas possessions, and sometimes they came to blows in defense of them. The English glory in the moment in 1588 when the Spanish Armada, bent on invasion, was decimated by ships under the command of Sir Francis Drake. It is a story every British schoolchild is told, even today.
More recently, the Spanish and British have had more in common as countries that have surrendered most of their former colonial possessions and joined in building a united Europe. King Juan Carlos is on record as saying that there is nothing urgent about the problem. He has said he is confident that a solution will eventually be found. But he has also made it clear that Spain must eventually regain sovereignty.
In 1981, when Britain's Prince Charles was married, he and the Princess of Wales decided to start their honeymoon from Gibraltar. This decision prompted the Spanish monarch to refuse to attend the wedding.
A month ago, when King Juan Carlos was putting the finishing touches on preparations for his visit to Britain, Spain's only aircraft carrier inexplicably steamed into Gibraltar's territorial waters. When Britain complained, the Spanish Foreign Ministry declared that the ship had done nothing wrong -- the waters into which it strayed, officials said, were Spanish, not British.
The incident served as a reminder of the highly sensitive character of the Gibraltar problem. Britain, though it would like to settle the question, knows that it cannot override the wishes of Gibraltarians who overwhelmingly prefer to remain British.
The British have attempted to keep Gibraltar off the agenda for the visit. The Spanish royal couple will stay with Queen Elizabeth at Windsor Castle, 20 miles outside of London. The invitation to address Parliament was put forward as a way of stressing British good will. The King will receive an honorary degree from Oxford University.
Prime Minister Thatcher would like to have Spain as an ally inside the EC, where Britain often finds itself under pressure from powerful countries such as France and West Germany to agree with policies that are not popular in London.
One point of disagreement between Britain and Spain, however, is on the subject of the EC's agricultural policy. Spanish farmers want the EC to help them modernize their industry. Britain wants to see EC spending on agriculture curbed.