DONALD Trump has been inaugurated as the 45th president of the United States.
Mr Trump was officially sworn in as president by the Chief Justice of the Supreme Court, promising to "faithfully execute the office of the president" and "preserve, protect and defend the Constitution of the United States" to rapturous applause from his supporters gathered below.
He was joined on the balcony of the US Capitol building by his family, the Obamas and, awkwardly, the Clintons, among other political leaders.
You can watch the continuing celebrations here.
"President Carter, President Clinton, President Bush, President Obama, fellow Americans, and people of the world, thank you," Mr Trump said.
"Every four years, we gather on these steps to carry out the orderly and peaceful transfer of power, and we are grateful to President Obama and First Lady Michelle Obama for their gracious aid throughout this transition. They have been magnificent. Thank you."
Mr Trump said his inauguration held "special meaning" as the moment the American people had regained control of their government.
"Today we are not merely transferring power from one administration to another, or from one party to another, but we are transferring power from Washington D.C. and giving it back to you, the people," he said.
"For too long, a small group in our nation's capital has reaped the rewards of government while the people have borne the cost.
Washington flourished, but the people did not share in its wealth. Politicians prospered, but the jobs left and the factories closed. The establishment protected itself, but not the citizens of our country.
"That all changes starting right here and right now because this moment is your moment. It belongs to you.
"January 20th, 2017 will be remembered as the day the people became the rulers of this nation again."
So, that was a giant middle finger to the Washington establishment. Populist to the core. His core supporters had to love this speech.— Matthew Dickinson (@MattDickinson44) January 20, 2017
The president reeled off a list of the problems he believed were afflicting the United States, and promised to solve them.
"At the centre of this movement is a crucial conviction that a nation exists to serve its citizens," he said.
"For too many of our citizens, a different reality exists.
"Mothers and children trapped in poverty in our inner cities; rusted-out factories, scattered like too many stones across the landscape, tombstones of our nation; an education system flushed with cash, but which leaves our young and beautiful students deprived of all knowledge; and the crime and the gangs and the drugs that have stolen too many lives and robbed our country of so much unrealised potential.
This American carnage stops right here and stops right now."
Turning to foreign policy, Mr Trump issued a "new decree" to the world, making it clear his administration would put "America first".
"We assembled here today are issuing a new decree to be heard in every city, in every foreign capital, and in every hall of power. From this day forward, a new vision will govern our land. From this day forward, it's going to be only America first, America first," he said.
"At the bedrock of our politics will be a total allegiance to the United States of America, and through our loyalty to our country, we will rediscover our loyalty to each other. When you open your heart to patriotism, there is no room for prejudice.
Mr Trump finished his speech with a reprise of his famous slogan from the election campaign.
"Together we will make America strong again, we will make America wealthy again, we will make America proud again, we will make America safe again and, yes, together, we will make America great again."
REACTION TO THE SPEECH
The consensus appears to be that Mr Trump delivered a curtailed version of his campaign stump speech. CNN's Jake Tapper summed it up pretty succinctly.
"It was pure populism," he said. "I think it will go down in history as one of the most radical speeches ever given by a president."
HILLARY'S AWKWARD TV MOMENT
Before the ceremony, Mr Obama and Mr Trump made the short trip from the White House to the Capitol in the same limousine, joining a motorcade that also carried their wives, Michelle and Melania, along with Vice President Joe Biden and Vice President-elect Mike Pence.
Everything went smoothly, but there was an awkward coincidence as Mr Obama and Mr Trump left the White House.
Simultaneous footage from the Capitol, displayed on a splitscreen by several US TV networks, showed the arrival of Hillary Clinton, Mr Trump's vanquished rival from last year's election.
Mr Trump and Ms Clinton's contrasting fortunes did not go unnoticed.
"It must be very difficult for Hillary Clinton to be here, having worked so hard to be here under completely different circumstances," CNN anchor Anderson Cooper noted.
"That moment, it gave me the chills," added co-host Dana Bash.
"It's just a reminder that no one ever knows what their fate is going to be.
And just to literally see Donald Trump walk out the door with President Obama, get into his car to go to his inauguration, and Hillary Clinton walking with her husband, who was president, knowing she never will be, at the very same time? Wow."
"The two men who denied her the presidency in one car," Cooper said.
As they took their places for the inaugural ceremony, Ms Clinton and her husband Bill received warm applause from the crowd.
OBAMAS' LAST WHITE HOUSE MEETING
Earlier, Mr and Mrs Trump were greeted warmly by the Obamas and taken inside the White House for an hour-long private meeting.
"Mr President-elect, how are you?" Obama asked, having deposited a letter to Mr Trump in the Oval Office and departed it for the last time. Mrs Trump handed Mrs Obama a gift in a Tiffany's box.
Hundreds of thousands of people gathered on the National Mall in the centre of Washington D.C. to celebrate a man whose short 19-month political career has defied all predictions, and many norms.
In the cool Washington dawn, his most ardent supporters ignored intermittent light rain and began to make their way by metro, car and on foot to take part in history.
"I've been waiting for this for a long time," said Thomas Mendenhall, 68, a retired banker from Missouri. "We just want change."
When Mr Trump descended the escalators of his glitzy New York tower in June 2015, his run for office and his supporters were dismissed and widely mocked.
In the primaries, Mr Trump dominated a crowded Republican presidential field with smash-mouth rhetoric and star power. He rode that same wave of anti-elite sentiment to victory over Democrat Hillary Clinton in the November election.
At 70 years of age, he is the oldest man ever to begin work in the Oval Office. But the real estate mogul and one-time television reality star is also a political neophyte - he will be the first president never to have held elected office, served in the government or the armed forces.
For Mr Trump's supporters, that is a central part of his appeal. "He's somebody that's not a politician," said 59-year-old Sandra Jackson-Carter, a salon owner from Bakersville, California.
"He's going to unite the country and make America great again," she said. "This is history. There's nothing better."
For his critics, Mr Trump's arrival in Washington on Thursday was more like a hostile takeover than a traditional changing of the guard.
Small demonstrations have popped up across the city centre, with shouts of "not my president" and "No Trump, No KKK, no fascist USA". Some tried to prevent supporters of Mr Trump from passing, but police intervened.
A much larger rally is planned for Saturday.