King Charles III's coronation: What happened overnight after monarch crowned in Westminster Abbey ceremony

King Charles and Queen Camilla were crowned on Saturday (local time) in a formal ceremony at London's Westminster Abbey.

New Zealand Prime Minister Chris Hipkins was among the 2000 invited guests, which included actresses Dame Joanna Lumley, Dame Judi Dench, Emma Thompson and singers Katy Perry and Lionel Richie.

Although Prince Harry attended the coronation alone, he was not present for the iconic photograph on Buckingham Palace's balcony and reportedly was on a return flight to the US just 28 hours after arriving in England, to make sure he could celebrate his son Archie's fourth birthday.

Meanwhile, dozens of anti-monarchy protesters have been arrested in London

Here's what happened overnight. 

US President Joe Biden sends his congratulations

In a tweet on Saturday night (NZ time), US President Joe Biden offered his congratulations to King Charles and Queen Camilla, citing the "enduring friendship" between the United States and United Kingdom.

"Congratulations to King Charles III and Queen Camilla on their Coronation. The enduring friendship between the U.S. and the U.K. is a source of strength for both our peoples. I am proud the First Lady is representing the United States for this historic occasion," he wrote.

King Charles
Photo credit: Getty Images

'What. A. Day.' 

Prince William and Catherine, Princess of Wales have commemorated the coronation on their social media accounts, sharing a series of photographs and footage of the occasion. 

In a tweet, the Prince and Princess of Wales simply wrote, "What. A. Day.", and offered their thanks to "everyone for making today happen". They also called the historic ceremony an "afternoon to remember".

Meanwhile, highlights from the coronation of King Charles III and Queen Camilla - the first coronation to take place in 70 years - have been shared to Westminster Abbey's social platforms.

'The atmosphere was phenomenal'

Speaking to media, New Zealand Prime Minister Chris Hipkins noted the "really nice atmosphere" within Westminster Abbey. 

"You could tell that a lot of good will towards the Royal Family was being expressed from around the world. The atmosphere outside was quite phenomenal," he said. 

He added that the event was "clearly very successful" and "followed keenly by people at home given the number of messages I received from people who saw me on the telly".

Hipkins was seated behind Australian Prime Minister Anthony Albanese and beside Canadian Prime Minister Justin Trudeau.

A glaring omission

Prince Harry, noticeably absent for the iconic photograph on Buckingham Palace's balcony following the coronation, reportedly boarded a plane back to the US to see his son Archie on his fourth birthday. 

'Spectacular scenes' for the coronation flypast 

"Spectacular scenes" from the Royal Air Force's flypast have been shared across social media, with the Red Arrows - the RAF's Aerobatic Team - painting the skies above London red, white and blue.

Katy Perry goes viral for seating struggle

Meanwhile, Katy Perry has prompted widespread hilarity on social media after footage of the popstar struggling to find her seat at King Charles III's coronation went viral. 

The 38-year-old, who is due to perform at the Coronation Concert at Windsor Castle, was spotted looking a little lost inside London's Westminster Abbey before the ceremony began. 

Perry was also caught losing her footing while departing the event, with a photographer snapping the moment she regained her balance after a slight stumble in her white stiletto heels.