Princess Martha Louise at King Carl XVI Gustaf's 70th birthday banquet

When Princess Martha Louise attended the banquet for the celebrations of Sweden's King Carl XVI Gustaf's 70th birthday in Stockholm on April 30, 2016, she wore a TSH silver one shoulder gown.

She attended the event with then husband, Ari Behn. Other European royals traveled to the Scandinavian country for the festivities. Queen Mathilde and King Philippe of Belgium, King Juan Carlos and Queen Sofia of Spain, Crown Prince Frederik, Crown Princess Mary, Princess Benedikte, and Queen Margrethe of Denmark, Princess Beatrix of the Netherlands, Hereditary Prince Alois and Hereditary Princess Sophie of Liechtenstein, Prince Albert of Monaco, and Princess Takamado of Japan were all in attendance to celebrate the King's 70th birthday. 

Oddly, Princess Martha Louise and Ari Behn were not in the group photo (below) from the banquet posted to the Swedish Royal Court's website. 

All of the guests at the banquet on April 30, 2016. Photo: Peter Knutson, Royal Court, Sweden 

All of the guests at the banquet on April 30, 2016. Photo: Peter Knutson, Royal Court, Sweden 

To celebrate His Majesty's birthday, a series of special events took place from April 25-April 30. The King was born on April 30, 1946. 

The events took place just a few days after the birth of Prince Alexander and therefore Princess Sofia only attended some of the events, choosing to stay behind with her newborn son instead.