It was one of the most important days of his life, which saw him crowned in a historic spectacle at Westminster Abbey.
So it's no surprise that King Charles wanted all aspects of his Coronation day to run like clockwork.
However, when arriving in the Diamond Jubilee State Coach at Westminster Abbey, royal fans wondered why he appeared agitated.
He could be seen talking to Queen Camilla in what appeared to be an irritated manner as they waited to exit the carriage.
And now a lip reader has revealed what he appeared to be saying - and it appears he was bemoaning keeping to the day's timetable.
The lip reader claims he uttered to his wife: "We can never be on time, there's always something..."
However, just minutes later, the monarch was out of the coach making his way through the Abbey ready to be crowned.
He was officially crowned by the Archbishop of Canterbury Justin Welby just after midday yesterday when St Edward's Crown was placed on his head.
After the lengthy ceremony, he and Camilla made their way back to Buckingham Palace in the gold state coach in wet conditions before appearing on the palace balcony.
There another lip reader picked up another comment, where the King appeared to be in awe of the spectacle - but not the weather.
Elisabeth Taunton claimed he said: "Isn't it beautiful... if only it wasn't so wet today."
Following yesterday's celebrations, thousands of people across the country will celebrate the Coronation Big Lunch today to celebrate the crowning of the King, causing a buzz of excitement for organisers.
A palace spokeswoman said big lunches will take place from Saturday to Monday “in a nationwide act of celebration and friendship”.
Alongside the thousands of street parties expected to be held at the weekend, people are encouraged to come together across the country for the Coronation Big Lunch.
The Duke and Duchess of Edinburgh will attend a big lunch in Cranleigh, the Princess Royal and Vice Admiral Sir Tim Laurence will visit a community street party in Swindon, and Princess Beatrice and Princess Eugenie will join a big lunch in Windsor.
Buckingham Palace said the Big Help Out on Monday will "highlight the positive impact volunteering has on communities across the nation".
A palace spokesperson said: "In tribute to the King's public service, it will encourage people to try volunteering and join the work being undertaken to support their local areas.
"The aim of Big Help Out is to create a lasting volunteering legacy from the Coronation weekend."
