"The death of my beloved Mother, Her Majesty The Queen, is a moment of the greatest sadness for me and all members of my family," he said in a statement following his mother's death.
"We mourn profoundly the passing of a cherished Sovereign and a much-loved Mother," he continued. "I know her loss will be deeply felt throughout the country, the Realms and the Commonwealth, and by countless people around the world."
He concluded his statement by saying, "During this period of mourning and change, my family and I will be comforted and sustained by our knowledge of the respect and deep affection in which The Queen was so widely held."
Read ahead for a full breakdown of what comes next for Charles.
Hugo Burnand-Pool/Getty King Charles III
When will Prince Charles become king?
Following the death of Queen Elizabeth, Charles assumed the role of king, effectively immediately. Clarence House confirmed that his official title will be King Charles III.
"Today the Crown passes — as it is has done for more than a thousand years — to our new monarch, our new head of state: His Majesty King Charles III," Prime Minister Liz Truss announced.
"With the King's family, we mourn the loss of his mother. And as we mourn, we must come together as a people to support him. To help him bear the awesome responsibility that he now carries for us all," Truss continued. "We offer him our loyalty and devotion just as his mother devoted so much to so many for so long. And with the passing of the second Elizabethan age, we usher in a new era in the magnificent history of our great country, – exactly as Her Majesty would have wished – by saying the words… God save the King."
With his accession upon the death of his mother, Charles inherits the responsibilities and privileges of a consecrated king, except one — he won't be allowed to publicly wear a crown until his coronation.
Tim Rooke - WPA Pool/Getty Prince Charles
When will King Charles III officially be proclaimed king?
As noted by AP, there are several formalities that take place after Charles ascends to the throne. The first step is the meeting of the Accession Council, which is made up of officials from the Privy Council, including senior Cabinet ministers, judges, and leaders of the Church of England. That is when Charles will be formally proclaimed the new sovereign.
Additionally, the new monarch will swear an oath before the Privy Council to preserve the Church of Scotland. This will be followed by the public proclamation of the new sovereign, which will be read publicly at St James' Palace in London as well as various locations in Edinburgh, Scotland, Cardiff, Wales, and Belfast, Northern Ireland.
When will King Charles III's coronation be?
Charles' formal coronation likely won't take place right away. In fact, Queen Elizabeth's coronation took place 16 months after her accession on Feb. 6, 1952, following her father King George VI's death.
"The coronation ceremony usually takes a year because it's seen as unseemly, really, to have a coronation ceremony straight after someone's death. It's a long period of mourning," Kate Williams, history professor at England's Reading University and author of Young Elizabeth: The Making of the Queen, tells PEOPLE.
When the coronation is announced, it will likely take place at Westminster Abbey, where it has been held for the past 900 years since William the Conqueror was crowned there.
Dominic Lipinski-WPA Pool/Getty Images Camilla, Duchess of Cornwall and Prince Charles
What will King Charles III's wife Camilla's title be?
Who is next in line for the throne?
Now that Charles has assumed the throne, the official British line of succession to the royal throne has shifted ever so slightly. Most notably, Charles' son Prince William is now first in line to the throne with his three children, Prince George, Princess Charlotte, and Prince Louis, following directly behind him.
Charles' second son Prince Harry is also now fifth in line to the throne with his two children Archie Harrison Mountbatten-Windsor and Lilibet Diana Mountbatten-Windsor following directly behind him.