Netherlands Prime Minister Mark Rutte signs the act of abdication of Queen Beatrix during an official meeting at the Royal Palace. Photo: Jerry Lampen/Reuters

Willem-Alexander became the first king of the Netherlands since 1890 yesterday, ascending a throne largely stripped of political power but still invested with enormous symbolic significance for the Dutch people.

At his investiture in Amsterdam’s 600-year-old Nieuwe Kerk, or New Church, the 46-year-old monarch swore an oath to uphold the Dutch constitution and stressed the need for unity at a time of economic crisis.

“I take office in a period when many in the kingdom feel vulnerable or uncertain.

“Vulnerable in their job or in their health, uncertain about their income or their immediate environment,” King Willem-Alexander said at his inauguration, attended by crown princes and princesses and other dignitaries.

“We can no longer take it for granted that children will be better off than their parents.

I take office in a period when many in the kingdom feel vulnerable or uncertain

“Our strength is therefore not in isolation but by cooperating.”

Willem-Alexander – a water management specialist, a useful expertise in a country where much of the land is below sea level – and his wife Maxima, a former investment banker from Argentina, are expected to bring a less formal touch to the monarchy.

April 30, or Queen’s Day, has always been an occasion for partying in the Netherlands, and Amsterdam has been awash with the colour of the House of Orange for days.

An estimated 25,000 people massed in Dam Square next to the Royal Palace to watch the abdication and inauguration being broadcast live.

Blinking back tears, former Queen Beatrix stepped out on to the balcony of the Royal Palace and presented her son to the crowds of cheering well-wishers.

“Some moments ago I abdicated from the throne. I am happy and thankful to present to you your new king,” said Beatrix, 75, who retired after 33 years in the role, following in the tradition of her mother and grandmother. She now takes the title of princess.

Willem-Alexander wore a royal mantle decorated with silver lions that has been used for investitures since 1815, although it has been repaired and altered at least twice over the past century, for the investitures of his mother and grandmother.

In accordance with tradition, he was not formally crowned because in the absence of a state church, there is no cleric available to carry out the coronation.

Instead, the crown and other jewels sat on a table beside him throughout the ceremony.

Queen Maxima wore a tiara and a full-length royal blue dress and cloak, which Dutch media reported was designed by Jan Taminiau of the Netherlands.