Donald Trump is now the 47th president of the United States, as well as the 45th president, a businessman – and a man who knows how to put on a show.
A litany of former presidents, Trump family members, tech royalty and world politicians attended the historic event.
As the 78-year-old entered the Rotunda, where the inauguration ceremony was moved to due to freezing temperatures outside, he was met with cheers and applause.
He reached for his wife Melania, who he awkwardly tried to kiss, and greeted his predecessor, Joe Biden, who was standing opposite the Trump family with now-former vice president Kamala Harris beside him.
Please use Chrome browser for a more accessible video player
Former US presidents in attendance included Bill Clinton with his wife, former presidential candidate and Trump rival Hilary Clinton.
Barack Obama was also there but without his wife Michelle, while George Bush attended with his wife Laura.
The newly-elected president gave his oath with his hands on two bibles, one given to him by his mother and the other being the Lincoln Bible, first used in 1861 to swear in the 16th US president.
The Republican, whose first term in power lasted between 2016 and 2020, then gave a speech in which he announced some sweeping measures on migration, climate change and gender rights.
On the eve of his inauguration, Mr Trump held a final rally in Washington DC, where he hinted at a blizzard of executive orders he would sign once he was back in the Oval Office.
Follow live: Trump inauguration
He was joined on stage by Elon Musk, his new government efficiency tsar, and then had a boogie with none other than the Village People, as they sang their hit YMCA.
After a candlelit dinner at the National Building Museum, he headed back to Blair House, known as The President’s Guest House, to prepare for one of the biggest days in the US political calendar.
On Monday morning, the inauguration began. It started at St John’s Church, known as the “Church of the Presidents”.
It is one of the most private events of an inauguration, with no TV cameras allowed inside the small, yellow church.
After the intimate prayer service, incoming vice president JD Vance went to meet outgoing VP Kamala Harris with their respective partners at the White House.
The Trumps headed to tea with the Bidens before the four of them were driven together to the swearing-in ceremony.
When Joe Biden was sworn in four years ago, then president Trump did not afford him the same tradition and instead skipped the whole inauguration.
While the 46th and 47th presidents took tea, the Rotunda filled with guests and musicians.
On the streets of Washington, thousands gathered to watch it live on screens.
Read more: Everyone wants a piece of Trump outside inauguration
