Dutch Queen Beatrix, right, Crown Prince Willem Alexander, second right, and his Argentinian-born wife Princess Maxima, second left, react during festivities marking Queen's Day in Makkum, northern Netherlands, Wednesday April 30, 2008. The Dutch celebrate Queen's Day, a Dutch national holiday marking the birthday of the Queen's mother.
Princess Maxima, center, and her husband Dutch Crown Prince Willem Alexander, in orange jacket behind, skate as the couple celebrate Queen's Day in Franeker, northern Netherlands, Wednesday April 30, 2008.
Princess Maxima, wife of Dutch Crown Prince Willem Alexander, engages in a traditional ball game during festivities marking Queen's Day in Franeker, northern Netherlands, Wednesday April 30, 2008.
Dutch Queen Beatrix, right, dances with a salsa dancer during festivities marking Queen's Day in Makkum, northern Netherlands, Wednesday April 30, 2008.
Dutch Queen Beatrix, right, reacts after dancing with a salsa dancer, left, during festivities marking Queen's Day in Makkum, northern Netherlands, Wednesday April 30, 2008.
Dutch Queen Beatrix, right, greets well wishers as she and her sister, Princess Margriet, second left, celebrate Queen's Day in Franeker, northern Netherlands, Wednesday April 30, 2008.
Argentinian-born Princess Maxima, left, and her husband Dutch Crown Prince Willem Alexander, skate as the couple celebrates Queen's Day in Franeker, northern Netherlands, Wednesday April 30, 2008.
Belgium
Belgium's King Albert II shakes hands with the crowd outside the Casino in Spa, Belgium, Thursday April 17, 2008. Together with Hungary's President Laszlo Solyom, who was on a 3-day official visit to Belgium, the King visited the old city center of Spa.
Hungary's President Laszlo Solyom, center, Belgium's Finance Minister Didier Reynders, right, and Belgium's King Albert II attend a performance at the Casino in Spa, Belgium, Thursday April 17, 2008. Solyom was on a 3-day official visit to Belgium.
Belgium's Prime Minister Yves Leterme, left, talks with Belgium's King Albert II during a private meeting at the Royal Palace in Brussels, Tuesday April 22, 2008.
Sweden
Grand Duke Henri of Luxembourg, centre and King Carl Gustaf, of Sweden, right, review the guard of honor at Stockholm Palace, Tuesday, April 15, 2008. The Grand Duke and Grand Duchess Teresa (not shown) were on a three-day official visit to Sweden.
From left, Grand Duchess Teresa, Grand Duke Henri of Luxembourg, Queen Silvia and King Carl Gustaf of Sweden, pose together in front of Stockholm Palace, Tuesday, April 15, 2008. The Grand Duke and Duchess were on a three-day official visit to Sweden.
Grand Duke Henri of Luxembourg, left, is welcomed by Crown Princess Victoria of Sweden, right, at Stockholm Airport, Tuesday, April 15, 2008. The Grand Duke and Duchess were on a three-day official visit to Sweden.
Britain
Britain's Prince Charles meets Alex Clarke, left, chairman of Britain's September 11th family support group, at a reception at Clarence House in London, Monday, April 28, 2008. As Patron of The British Memorial Garden, The Prince of Wales hosted a reception to mark the 5th anniversary of the founding of the New York garden which honors the British victims of the World Trade Centre attacks on Sept. 11, 2001.
Members of the King's Troop Royal Horse Artillery fire a 41-gun salute to mark Britain's Queen Elizabeth II's 82nd birthday, at Hyde Park in London, Monday, April 21, 2008. On Dec. 20, the British queen became the oldest person ever to reign in Britain, beating the record set by Queen Victoria. She is one of only five kings or queens since the 1066 Norman Conquest to reign for more than half a century.
Members of the King's Troop Royal Horse Artillery arrive prior to firing a 41-gun salute to mark Britain's Queen Elizabeth II's 82nd birthday at Hyde Park in London, Monday, April 21, 2008. The event celebrated the queen's actual birthday, not her official one, which is marked with outdoor events in June, when the weather is nicer.
Britain's Prince Charles, with his wife Camilla, Duchess of Cornwall, left, look at a policeman's helmet given as a gift during their visit to Charing Cross Police Station, London, Wednesday, April 23, 2008. During his visit, the prince met uniformed officers and staff and saw some of the equipment and facilities used by police officers.
Jordan
King Abdullah II of Jordan, right, meets former U.S. President Jimmy Carter, left, in Amman, Jordan, Sunday, April 20, 2008. Carter was on a Middle East tour. At center left is Carter's wife, Rosalynn.
Queen Rania of Jordan attends the 4th IOC World Conference on Women and Sport, in South Shuoneh, west of Amman, Jordan. Top women athletes gathered in Jordan to discuss boosting female participation in the Olympics and other sporting events.
King Abdullah II, right, and his wife Queen Rania, center, receives Sen. John McCain, left, at the Royal Palace in Amman, Jordan. McCain is the likely Republican presidential nominee.