Decked in the national orange colour, dancing to music, and eating orange-glazed pastries, many in the Netherlands are marking King’s Day on Saturday, celebrating the birthday of their monarch.

As King Willem-Alexander celebrated his 57th birthday with his family in the northeastern city of Emmen, people across the country engaged in the traditional “free markets” held on that day, selling second-hand toys, books and other items.

Others toured through the historic canals of the capital, Amsterdam as orange smoke from flares held aloft one boat drifted over vessels of all shapes and sizes jostling for space on a busy canal.

Netherlands King’s Day
Two girls sell orange pastries during King’s Day celebrations in Amsterdam (Peter Dejong/AP)

“Celebrating your birthday with your own family is the most beautiful thing you can experience. I’m very happy everybody is back,” Willem-Alexander told Dutch broadcaster NOS during a walkabout in Emmen, 190 kilometres (120 miles) northeast of the Dutch capital.

An annual poll published by the NOS for King’s Day showed Willem-Alexander’s popularity edging up very slightly since last year to 6.6 out of 10. His Argentina-born wife, Queen Maxima, scored 7.1 out of 10 in the poll of 1,015 people, conducted earlier this month.

The royals’ popularity took a hit during the Covid-19 pandemic after Willem-Alexander and his family went on holiday to Greece during a partial lockdown.

Netherlands King’s Day
An orange-clad man and his orange-clad dog listen to a girl playing violin during King’s Day celebrations in Amsterdam (Peter Dejong/AP)

The royals cut short their break amid national uproar and Willem-Alexander took the unusual step of issuing a video message to express his regret and contrition for the trip.

The king’s three daughters, Amalia, Alexia and Ariane have all spent time out of the country recently — Ariane has been studying in Italy while Alexia has taken a gap year to travel.

The eldest and heir to the Dutch throne, Amalia, also returned ahead of the king’s birthday after being forced to leave her student accommodation in Amsterdam and move to Madrid following threats from the criminal underworld.

Amalia, 20, who is studying politics, psychology, law and economics, told NOS she was “extremely grateful to everybody who made it possible” to live in Spain, where she said she was able to enjoy more freedom than in the Netherlands.

But, she added: “I’m glad to be back.”