Millions of viewers watched King Charles III crowned in a meticulously-planned ancient ceremony but it was the unexpected moments that got many people talking.

1. Penny Mordaunt wields swords

UK member of Parliament Penny Mordaunt caused a flurry of activity on social media as she played a starring role at the Coronation - holding ceremonial swords for more than an hour.

On Twitter many pointed out the Conservative MP's strength, even winning praise from her party's political foes.

"Don't let anyone ever say I never say anything positive about the Tories... I am in awe of @PennyMordaunt arm and shoulder strength," former Labour spin doctor Alastair Campbell tweeted.

While Mordaunt's custom-made teal outfit - with a matching cape and headband with feather embroidery - also caught people's attention, with many drawing comparisons with Henry VIII's second wife Anne Boleyn.

One woman tweeted: "Penny Mordaunt has absolutely stolen the show at the Abbey today! She is rocking that Anne Boleyn look!"

The MP and Leader of the House of Commons was heavily involved in the ceremony through her role as Lord President of the Council - an ancient role.

She carried the 17th century Sword of State made for Charles II into Westminster Abbey, and exchanged it for the Jewelled Sword of Offering, which she delivered to the archbishop.

She then carried the Jewelled Sword of Offering, with hilt encrusted with diamonds, rubies and emeralds, for the rest of the service and walked with it in front of the King as he left the Abbey.

Notably, she becomes the first woman to carry and present the sword - which symbolises royal power and the King accepting his duty and knightly virtues.

Speaking to Times Radio before the ceremony, she joked she had been preparing by "doing some press-ups".

2. Princess Charlotte and Prince Louis

Britain's Princess Charlotte of Wales and Britain's Prince Louis of Wales arrive at Westminster Abbey in central London on May 6, 2023. Photo: PHIL NOBLE / AFP

There was a tender moment between the Prince and Princess of Wales's children. Prince Louis, five, when he held the hand of his older sister Princess Charlotte as they walked into Westminster Abbey.

The prince, the youngest of Prince William and Catherine's children, was on his best behaviour, having stolen the show at previous royal events including Queen Elizabeth II's Platinum Jubilee when he appeared to find the flypast a bit noisy while on the

Buckingham Palace balcony.

This time, the prince nudged his father to point out something in the distance during the flypast and debuted a new, rather exaggerated, wave.

3. Gospel choir bring a modern twist to ancient ceremony

A gospel choir added a rather modern twist to the ancient ceremony.

The Ascension choir were handpicked and specially brought together for the occasion. Dressed in all white, the group of singers sang beautifully and swayed as they performed specially composed piece Alleluia.

They proved a hit with Catherine who gave a beaming smile as she listened.

4. When music royalty meets actual royalty

American singer-songwriter Katy Perry takes selfie photos with guests for the King's Coronation at Westminster Abbey in central London on 6 May, 2023. Photo: Gareth Cattermole / POOL / AFP

Singer Katy Perry turned heads in a fabulous lilac Vivienne Westwood matching jacket and skirt, and fascinator.

But the Firework singer caught viewers' eyes for another reason as she had a spot of bother finding for her seat.

She was seen walking up and down the Abbey searching for it.

"Katy Perry not finding her seat is so me," tweeted one Perry fan.

The pop star, who happily took selfies with other guests, will be performing at the Coronation Concert in Windsor alongside Lionel Richie on Sunday.

5. Prince William kissed father

Prince William, Prince of Wales, kisses his father, King Charles III, wearing St Edward's Crown, during the Coronation ceremony inside Westminster Abbey in central London on 6 May, 2023. Photo: Yui Mok / Pool / AFP

The King and the Prince of Wales shared a touching moment when Prince William paid homage to his father.

Prince William got down on one knee to pledge his loyalty to the King, before kissing him on the cheek.

The King was then seen to say a few words to his eldest son.

In a break with tradition, the prince was the only blood prince to pay homage.

- BBC