It also creates a shift in the line of succession underneath him.
Once second in line to the throne, William – whose new title is the Duke of Cornwall and Cambridge – is now heir to the throne. His son Prince George, is second in line.
Princess Charlotte retains her place as third in line to the throne. The law used to mean that male heirs took precedence, meaning that her younger brother would have jumped over her.
But a change in the law when William and Kate were expecting their first child has stopped this happening.
Louis is fourth in line to the throne, and Harry is back up to fifth.
Lack of royal title is no barrier to the throne, and Archie is sixth even though he is simply Master Archie Harrison Mountbatten-Windsor.
The Duke and Duchess of Sussex's daughter Lilibet, who was named after the Queen's nickname, is now seventh in line to the throne.
After Charles’s sons and their children, the line of succession jumps back to the Queen’s other children. As the law was not changed in time for Anne to benefit, the line goes to Prince Andrew, her second son, who is eighth.
His eldest daughter, Princess Beatrice, is ninth and her daughter, Sienna Elizabeth Mapelli Mozzi, 10th . Then it's Princess Eugenie at 11th and her son, August Philip Hawke Brooksbank, 12th.
Then the line returns to Prince Edward, who is 13th, and his children. His older daughter is also trumped by her younger brother, like her aunt Princess Anne.
So James, the Viscount Severn, is 14th, and Lady Louise Windsor, is 15th.
Then Anne, the Princess Royal, has her place at 16th. Her son Peter Phillips is 17th, and his children, Savannah and Isla are 18th and 19th.
Zara Tindall is 20th, and her children, Mia and Lena, and Lucas make up 21st, 22nd and 23rd on the list.
Once the Queen’s direct descendants are covered, the line jumps back to the descendants of her younger sister, Princess Margaret, who died in 2002.
She had one son, the current Earl of Snowdon, and he has a son and daughter, Charles Armstrong-Jones, the Viscount Linley, and Lady Margarita Armstrong-Jones. They take up positions 24, 25, and 26.
She also had a daughter, who is younger than the Earl of Snowdon, called Lady Sarah Chatto. Lady Sarah has two sons, Samuel Chatto and Arthur Chatto. The trio are 27th, 28th, and 29th in line to the throne.
Those positions cover all the direct descendants of the Queen’s father, the former king, and so the line then jumps back to his late brothers’ descendants, the children and grandchildren of Prince Henry and Prince George.
These include lesser known working royals like Prince Michael of Kent, and the Duke of Gloucester, the Queen’s cousins.
They have long supported the throne in their work with charities across the UK, but the likelihood they would ever accede to the top job is slim.
Watch: How the Royal Baby alters the line of succession