Nor would they have guessed that many Swedes professed themselves to be apathetic about the celebrations, and that people were worried about the day being hijacked by extremist demonstrations.
Thousands made their way to the historic heart of the capital, which was decked out in blue and gold for the occasion.
Celebrations for the first National Day to be declared a public holiday were held in towns and cities up and down the country. Yet perhaps naturally enough the national celebrations centred on Stockholm, the palace and the Royal Family.
The festivities were kicked off by the young royals at ten o’clock, as they opened the palace doors to the public. Visitors were given free guided tours of the state apartments.
And just before the palace doors were officially opened, in a gesture that couldn’t have worked better if planned by the palace spin doctors themselves, a little girl broke from the crowds to present a bouquet to Princess Madeleine. Crown Princess Victoria was also given a posy by the girl, identified by Aftonbladet as two-year old Lovisa Simonsson.
In the late afternoon King Carl Gustaf and Queen Silvia set off in a carriage procession to the Skansen open-air museum for a National Day concert. Their carriage was followed by another carrying the princesses and Prince Carl Philip, and the procession was greeted en route to Skansen by a mixture of cheering crowds and curious tourists.
At Skansen the family was joined by 89-year old Welsh-born Princess Lilian, widow of the king’s uncle, Prince Bertil.
In a good omen for the new public holiday, the rain which was hanging in the air all day did not break out until after the royals had been entertained by stars including the Swedish cast of Abba musical Mamma Mia, and both the Riksdag’s speaker Björn von Sydow and the king had given speeches.
“This is the time at which we honour the motherland together,”said the king, adding that the occasion had taken on “a particularly festive atmosphere now that it has been named as a public holiday.”
National Day was also celebrated in other cities around the country. Göran Persson, the prime minister, joined locals in Södertälje, where he gave a speech in which he welcomed the “enormous diversity of cultures” in modern Sweden, which he said “make Sweden more successful”.
In Malmö, the Swedish flag flew together with the EU flag in the city centre, and the governor of Malmö gave a speech to crowds in Stortorget.
In Gothenburg, the day was marked by a “flag parade” of soldiers and representatives of voluntary organisations through the city centre to the Liseberg theme park.