The Coronation will officially see King Charles crowned as monarch in a spectacular ceremony at Westminster Abbey.
But his reign actually began almost eight months ago when his late mother the Queen died - meaning he became King then.
He has not had an easy ride since - especially when it comes to his son Prince Harry and wife Meghan Markle - and has also had to contend with two prime ministers, political turmoil and a cost of living crisis.
But luckily, he has a close-knit group at his side, who have helped him navigate the early months of his reign and will likely be at his side for the Coronation and beyond.
Sir Clive Alderton
Sir Clive Alderton began working for the King in 2006 when he was Prince of Wales and quickly rose through the ranks to become his private secretary.
He is currently sharing the role with the late Queen's private secretary Sir Edward Young, who it's said will step aside after a transition period.
Sir Clive is a career diplomat who became Britain's ambassador to Morocco after a previous six-year stint as an aide at Clarence House between 2006 and 2012.
Always sharply dressed with blonde combed-over hair, he regularly accompanies Charles on overseas tours.
Queen Consort Camilla in particular is said to "adore" him, one source told the Times.
In 2020, he is said to have played a key role in the negotiations of Harry and Meghan's Megxit deal - and according to The Times, friends suggest he came up with the phrase "recollections may vary" in response to their bombshell Oprah Winfrey interview.
In Prince Harry's controversial memoir, Spare, which was released earlier this year, Sir Clive is referred to as the Wasp.
In the book, Harry recalled how you could tell him that the sun rises in the mornings and he would have you question what a morning was.
Harry claimed it was easy to misjudge 'the Wasp' because of his appearance, but if you pushed back you would be put on his 'list'.
"A short time later, without warning, he'd give you such a stab with his outsized stinger that you'd cry in confusion. Where the f*** did that come from?" he wrote.
Peter St Clair-Erskine
Peter St Clair-Erskine is the former master of the household at Clarence House - and recently was appointed Lord Steward by the King and is also a personal secretary to both Charles and Camilla.
An Old Etonian and a member of the House of Lords, he formerly worked for the Metropolitan Police, where he held the role of head royalty protection for 10 years.
In 2014, he started working for Charles and Camilla as Master of the Household to The Prince of Wales and was appointed to his most recent position earlier this year, when he was officially given his 'wand of office'.
Lieutenant Colonel Jonathan Thompson
One aide who seems to have been at Charles' side ever since he came to the throne is equerry Lieutenant Colonel Jonathan Thompson.
He is of the 5th Battalion Royal Regiment of Scotland and is often seen wearing a traditional kilt. He previously worked for the late Queen too.
Equerries are drawn from the armed forces and are required to assist the royals both inside their personal residences and when out and about on public engagements.
Since being thrust into the spotlight, the 39 year old has developed a strong online following with many swooning over him.
One big fan wrote on Twitter: "Major Jonny Thompson is a tremendous hunk!"
Another remarked: "We need more footage of the rather handsome kilted Major Jonny Thompson."
While one said: "I think I'm getting a wee crush on King Charles' new royal equerry."
Sir Nicholas Soames
Sir Nicholas Soames is a grandson of Sir Winston Churchill and has been a close friend of the King's since they were teenagers.
The former MP is known to be a close confidant of Charles and even worked as an equerry for him in the 1970s.
Two days after the Queen's death, Sir Nicholas spoke about how his friend's life would change after taking the throne - and how he will handle the pressure.
He told BBC Radio 4's Today programme: "As the King said last night, as he embarks on his new responsibilities, clearly his life will change, and his views and the way that he conducts himself will observe, of course, the constitutional principles.
"He made absolutely plain that he intends to uphold the constitutional principles at the heart of the nation that he understands very well.
"The Prince of Wales has served a long apprenticeship at the feet of an absolute master and he knows very well what the constitutional obligations are."
Queen Camilla
One person certainly at the heart of the King's inner circle is his 'darling' wife, Queen Camilla.
She too has been an almost constant at his side since his accession and according to former BBC royal correspondent Jennie Bond she knows how to "soothe and calm him".
She told the Mirror: "She is his rock; the foundation on which his Kingship will succeed or founder."
Meanwhile in a book called The New Royals, its author Katie Nicholl, a royal expert, says that Camilla even sometimes "calls the shots".
She writes: "Charles often runs ideas and speeches by his wife and there are times Camilla calls the shots."
Prince William
And as well as his wife, Charles will also have his eldest son and new Prince of Wales, Prince William, to lean on.
Images of William standing alongside his father and the Queen Consort at the historic Accession Council ceremony last September in the days after the Queen's death showed "a modern monarchy evolving before our very eyes", says the Mirror's Royal Editor Russell Myers.
He added: "It appears that Charles has realised he must evolve with his new role and surround himself with trusted lieutenants such as William.
"He must also prepare his heir for the future and it is surely no coincidence their relationship has strengthened in recent times, with this in mind.
"The Prince of Wales also realises that the time has now come for him too to realise his own destiny."
