Traditionally, the birth of a younger male heir would have displaced Princess Charlotte’s line of succession.
However, in 2011 leaders of 16 British Commonwealth countries voted to alter the law.
The Succession to the Crown Act 2013 meant younger males could no longer take precedence to the throne over their older female siblings.
This means that Princess Charlotte is still fourth in line to the throne with the new Prince of Cambridge fifth.
This rule only takes place for children born after 2011. Therefore Prince Edward’s son James, Viscount Severn, who was born in 2007, is above his sister Lady Louise, born in 2003, in the line to the throne.
How does the royal line of succession work?
If Queen Elizabeth II abdicates or dies, the throne will be passed to the Prince of Wales.
After Prince Charles, next in line is Prince William, the Duke of Cambridge.
Third in succession is Prince George, then Princess Charlotte and fifth in line is the new baby.
Prince Harry is sixth in line for the throne and Prince Andrew, son of the Queen and Prince Philip, is seventh in line.
His daughter with the Duchess of York, Princess Beatrice, is eighth in the line of succession and Princess Eugenie is ninth in line.
If Prince Harry and Meghan Markle have children, their offspring will be pushed above Prince Andrew in the royal line of succession. This will put their first child seventh in line to the throne.
How did Queen Elizabeth II become the Queen?
The Queen’s grandfather King George V died in 1936 and her uncle, Edward VIII succeeded as king.
However, in the same year Edward abdicated after he proposed to divorced socialite Wallis Simpson, who had two ex-husbands.
This caused Elizabeth’s father, George VI to became king – making her next in line for the throne.
In 1952, King George VI died, allowing Elizabeth to succeed as the Queen of England.