As Queen Silvia, Crown Princess Victoria, Prince Daniel and two-year-old Princess Estelle looked down from the royal balcony, King Carl XVI Gustaf of Sweden walked out in the palace courtyard to meet his well-wishers.
The king's family looks on during his 68th birthday ceremony at the palace. Photo: TT
Two young well-wisher try to catch a glimpse of the king. Photo: TT
The 68-year-old also received a greeting from afar, as his New York-based youngest daughter Princess Madeleine published a photograph of infant Princess Leonore surrounded by balloons.
"Happy Birthday Grandpa", the Facebook post read.
The picture has so far attracted some 5,000 likes on the social media site.
IN PICTURES: King Carl VI Gustaf's life and work
Her grandfather has spent more than four decades on the Swedish throne, travelling the width and breadth of Sweden to meet the people.
The king visits a paper factory in 1978. FiIe photo: TT
Part of his role as king also entails welcoming foreign dignitaries to the country, and representing Sweden abroad.
The king and queen meet their British counterparts in 1983. File photo: TT
An opinion poll published in February found that more than 50 percent of Swedes want the king to abdicate, and give way instead to Crown Princess Victoria.
READ ALSO: Swedes want Victoria on the throne