Following a thanksgiving service in Stockholm's Palace Chapel, which was attended by the king's family and royal visitors from Japan, Spain, the Netherlands, Norway and Denmark, the Swedish monarch greeted his subjects from the palace ramparts.
He was joined by his family – including 2-month-old Prince Oscar, who was born on March 2. Dressed in a blue bonnet, which matched big sister Princess Estelle’s powder blue coat, he made his public debut in the arms of proud mom Princess Victoria as the crowd cheered below.
The prince, who was swaddled in a baby blanket, seemed to take the occasion in stride, enjoying a nap during the celebrations.
In the arms of dad Prince Daniel, Princess Estelle kept an eye on her new sibling before enjoying the music from a 1,500-strong choir.
New parents Princess Sofia and Prince Carl Philip, who welcomed Prince Alexander on April 19, were also in attendance.
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Prince Oscar was following in a Bernadotte family tradition since his big sister made her public debut on the same balcony during the king’s birthday four years before.
Earlier in the day, the 4-year-old princess delighted onlookers by insisting on greeting clergymen as she left the royal chapel, before shaking hands and kissing cheeks with other royal guests. The scene-stealing princess then joined in musical tributes to the king, enthusiastically clapping her hands.
After Princess Estelle and her new baby brother had been put to bed, King Carl XVI Gustaf hosted a banquet at the palace.
Featuring a DJ and a live band, Abba's “Dancing Queen,” was accompanied by a dancing king, according to the Swedish outlet Svenskdam, which reported that the monarch left the party before it broke up shortly before 6 a.m. on Sunday morning.
King Carl XVI Gustaf ascended the Swedish throne in September 1973 and married German commoner Silvia Sommerlath three years later. The royal couple has three children and five grandchildren.
Prince Oscar, their second youngest grandchild – and third in line to throne – is expected to be christened on May 27.