Right from the start their relationship was an exceptional one. Crown Prince Carl Gustaf met his future bride in the summer of 1972 at the Olympic Games in Munich. The pair "clicked" right away, according to the now-King, but Sofia, an interpreter who speaks six languages, had no royal blood, which made her an unsuitable choice in the eyes of then-King Gustaf VI Adolf.
But three years into Carl's reign in March 1976, the couple announced their engagement and tied the knot three months later. Silvia became the first queen to have a career, and 40 years later the pair is still going strong – happily supporting each other through duty, children, grandchildren and all problems big and small. Today, as the royal couple celebrate their milestone anniversary, we look back at some of their most loving moments...
Sweden's King Carl XVI Gustaf married the love of his life Silvia Sommerlath on June 19, 1976 at Stockholm Cathedral. The German-born bride spent many of her formative years in Brazil before returning to Germany in 1957. Silvia was working as an educational host at the 1972 Olympics when she first encountered Sweden's future King.
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The delighted King held hands with his bride after their ceremony. When asked about the type of woman he would like to marry, Carl said: "She may be a secretary or a government official. That does not matter. The important thing is love.”
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Carl and Silvia were delighted to exchange vows during their wedding ceremony in 1976, which was performed by the Archbishop of Uppsala, Olof Sundby. The night before the wedding a Royal Variety Performance was held in honour of the couple, where national icon ABBA performed their hit "Dancing Queen" for the first time in tribute to their country's new queen.
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Then-French President Valéry Giscard d'Estaing welcomed Carl and Silvia to the Élysée Palace in Paris shortly after their wedding. The President hosted a dinner in honour of the royal couple alongside his wife and First Lady Anne-Aymone Giscard d'Estaing.
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In August 1977 the newlyweds were delighted to welcome their first child, daughter Victoria. Here the trio are pictured at the Swedish royal family's summer residence, Solliden Palace, less than a month after Victoria's arrival.
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One month into their lasting marriage, Silvia and Carl seemed relaxed in one another's company and at ease with their royal roles. Silvia has modernized the position of Queen during her time on the throne and has enjoyed an equal relationship with her husband.
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The parents of three have enjoyed a close relationship with each of their children: Victoria, Carl Philip and Madeleine. All three of their heirs are now married and have welcomed children themselves, giving Carl and Silvia five grandchildren.
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The Olympics will always hold a special place in the hearts of Carl and Silvia and the royal couple looked delighted to be attending the 2014 winter games in Russia, where they enthusiastically cheered on their home team, who took home a gold medal in cross-country skiing.
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Lending a dapper hand, the King graciously helped his wife descend from their carriage as they arrived at the Royal Swedish Opera in honour of King Carl's 70th birthday in April 2016.
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The proud parents celebrated the 38th birthday of their daughter Victoria, Crown Princess of Sweden. A special outdoor concert was held to mark the occasion, which Victoria attended with her husband Prince Daniel and young daughter Estelle, then 3, who waved adorably to crowds during the family outing.
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Sweden's reigning royals attended a gala dinner in honour of the wedding between Prince Guillaume, Hereditary Grand Duke of Luxembourg and Countess Stéphanie Marie Claudine Christine de Lannoy at Luxembourg's Grand-Ducal Palace in 2012.
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The king and queen are always happy in one another's arms. The pair showed off their dance moves when Carl celebrated 40 years on the throne in 2013. The Royal Palace in Stockholm hosted a celebration to mark the milestone.
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The royal couple waved and smiled at the crowds as they attended the Victoria Day celebrations – in honour of their oldest daughter – at the family's Borgholm-based summer residence of Solliden Castle in July 2013.
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Today the royal couple looks happier than ever. In this official portrait, released along with three others to mark the King's 70th birthday, the pair are dressed to the nines and look exceptionally regal. Two of the portraits featured Carl alone and two included his loving wife.
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