AMSTERDAM -- Willem-Alexander became the first Dutch king in more than a century Tuesday and pledged to use his ceremonial position as head of state to help steer his country through uncertain economic times.
The generational change in the House of Orange-Nassau gave the Netherlands a moment of celebration, pageantry and brief respite as this trading nation of nearly 17 million struggles through a lengthy recession brought on by the European credit crisis.
Visibly emotional, the much-loved Beatrix ended her 33-year reign as queen in a nationally televised signing ceremony as thousands of orange-clad people cheered outside. Millions more were expected to watch on television.
Just over four hours later, King Willem-Alexander, wearing a fur-trimmed ceremonial mantle, swore an oath of allegiance to his country and the constitution in the historic New Church.
In a speech in the church, Europe's youngest monarch underscored the ceremonial nature of his monarchy in this egalitarian society but also the symbolic and economic value a king can deliver on state visits aimed at drumming up trade.
"I will proudly represent the kingdom and help discover new opportunities," he said.
The investiture ceremony was the final formal act on a day of high emotion within the House of Orange-Nassau and was to be followed by an evening boat tour around the historic Amsterdam waterfront.
The new king gripped his mother's hand and looked briefly into her eyes after they both signed the abdication document in the Royal Palace on downtown Amsterdam's Dam Square.
Beatrix looked close to tears as she then appeared on a balcony decked out with tulips, roses and oranges, overlooking 25,000 of her subjects.
"I am happy and grateful to introduce to you your new king, Willem-Alexander," she told the cheering crowd, which chanted: "Bea bedankt" ("Thanks Bea.")
Moments later, in a striking symbol of the generational shift, she left the balcony and King Willem-Alexander, his wife and three daughters -- the children in matching yellow dresses and headbands -- waved to the crowd.
"Dear mother, today you relinquished the throne. Thirty-three moving and inspiring years. We are intensely, intensely grateful to you," the new king said.
The former queen becomes Princess Beatrix and her son becomes the first Dutch king since Willem III died in 1890.
The 46-year-old king's popular Argentine-born wife became Queen Maxima and their eldest of three daughters, Catharina-Amalia, became Princess of Orange and first in line to the throne.
Willem-Alexander has said he wants to be a 21st century king who unites and encourages his people; not a "protocol fetishist," but a king who puts his people at ease.
He will do so as unemployment is on the rise in this traditionally strong economy. European Union figures released Tuesday showed Dutch unemployment continuing to trend upward to 6.4 percent -- still well below the EU average of 10.9 percent, but higher than it has been for years in the Netherlands.
"I am taking the job at a time when many in the kingdom feel vulnerable and uncertain," Willem-Alexander said. "Vulnerable in their work or health. Uncertain about their income or home environment."
Amsterdam resident Inge Bosman, 38, said she doubted Willem-Alexander's investiture would give the country much of an employment boost.
"Well, at least one person got a new job," she said.
Els Nederstigt, 38, said she got up at 5:30 a.m. to travel to Amsterdam and sat on a camping stool close to the Royal Palace wearing an orange cowboy hat and tiara.
"It's a special moment. I was a very small girl when Beatrix came to the throne so this is the first change in the monarchy I can really experience," she said. "We were here when Willem-Alexander and Maxima got married and what you remember is that you were there -- you forget how early you had to get up and how tired you were."
The square was overwhelmingly orange, but one blue and white Argentine flag being held up in front of the palace was emblazoned with the Dutch language text: "Netherlands thanks for loving and having faith in Maxima."
The day is expected to be a huge party culminating in a boat trip by the new king and queen around the Ij waterway, but security also was tight with thousands of police -- uniformed and plain clothes -- and an untold number of civil servants assisting in the logistics.
Police arrested two protesters on Dam Square -- one of them wearing a white shirt indicating he was a republican -- shortly after the abdication for not following officers' orders to leave. Amsterdam police released both without charge shortly afterward and apologized for detaining them.
At an anti-monarchist demonstration on the nearby Waterloo Square, protesters dressed in white instead of orange and carried signs mocking Willem-Alexander.
"Monarchy is a sexually-transmitted disease," one sign said.
Amsterdammer Jan Dikkers said he came out to show his disapproval for the inauguration of Willem-Alexander, who he said Dutch people only tolerate because "people like his wife."
He said Beatrix is overrated.
"People say the queen did a 'good job', but she didn't really do any job," Dikkers said. "Maybe she seems like a nice person, so people like her, but there's a difference."
The celebrations were peaceful across the city, in stark contrast to Beatrix's investiture in 1980 when squatters protesting a chronic housing shortage fought with police, and clouds of tear gas drifted through parts of the city.
The airspace above Amsterdam was closed Monday for three days. Dutch police swept Dam square for bombs, with assistance from German agents with sniffer dogs.
Royal guests from 18 countries are attending, including Britain's Prince Charles and his wife, Camilla, and the Japanese Crown Prince Naruhito and Crown Princess Masako. Charles was also in attendance when Beatrix was crowned in 1980.
Observers believe Beatrix remained on the throne for so long in part because she was seen as a stabilizing factor in the country that struggled to assimilate more and more immigrants, mainly Muslims from North Africa, and shifted away from its traditional reputation as one of the world's most tolerant nations.
In recent years, speculation about when she might abdicate had grown, as she endured personal losses that both softened her image and increased her popularity further as the public sympathized.
Her husband Prince Claus died in 2002; and last year her youngest son, Prince Friso, was hit by an avalanche while skiing in Austria and suffered severe brain damage. Friso remains in a near comatose state.