The surprise guest at King Charles' Coronation we didn't expect to attend

King Charles III's Coronation is underway, with the ceremony taking place at London's Westminster Abbey on 6 May. 

Guests have travelled far and wide to watch the crowning ceremony at the historical London venue, while royal fans have gathered along The Mall and outside of Buckingham Palace to watch the procession. 

There has been speculation over who will, and will not, be attending the momentous occasion in royal history over the last few months.

Sarah Ferguson has claimed she was not invited to the coronation because of her divorce from ex-husband Prince Andrew, while there were fears Prince Harry would pull out. 

Harry has made the journey from the US to the UK to watch his father's Coronation, while his wife Meghan Markle stays in California with their two children Archie and Lilibet. 

It was previously reported that Prince Louis would also be absent from the ceremony, although his older brother Prince George has an important role to play on the day. 

However, it turns out the youngest member of the Cambridge family has attended the coronation, and we couldn't be happier. 

As the royals made their way to Westminster Abbey cameras panned to one carriage with Prince Louis - who recently celebrated his fifth birthday - in the backseat. 

In true Louis fashion, he looked out the window at the crowds of people who collected for the royal celebration and appeared to subtly wave to the people as he passed by.

Unlike previous royal engagements, Louis refrained from sticking his tongue out at the crowds, but instead, had quite a serious facial expression.

However, there is still time, and plenty more celebratory events to come, for Louis to entertain crowds - watch this space!

As the ceremony commenced Louis sat beside his parents, the Prince and Princess of Wales, as well as his big sister Princess Charlotte, at Westminster Abbey.

However, The Telegraph has reported Louis will not stay for the entire two-hour ceremony but will slip out with royal aides, although he will rejoin his family after the ceremony, at around 1 pm to join the procession to Buckingham Palace.