Succession laws dating back 300 years have been overturned at a recent international meeting involving the heads of state from several countries - clearing the way for ladies to claim the throne ahead of their male siblings.
At the 2011 Commonwealth Head Of Government Meeting (CHOGM) held in Perth, Western Australia, the 16 world leaders in attendance voted unanimously to allow changes to be made to a range of legislation that will allow the first born of the royal family to become the King or Queen - regardless of the child's gender.
This means that should the Duke and Duchess of Cambridge have a baby girl as their first born, their daughter would be first in line over any younger brothers.
Under old UK laws such as the 1701 Act of Settlement and the Royal Marriages Act 1772, the only time a female heir could ascend the throne was when the current monarch had not born any sons - as was the case when Queen Elizabeth II was crowned.
A ban on the monarch being married to a Roman Catholic was also overturned by the meeting, as was legislation requiring the direct descendants of George II to seek the legal consent of the reigning monarch getting married.
Speaking on the successful vote, Australian prime minister Julia Gillard said that she felt it was
an extraordinary moment.
She said: "You would expect the first Australian woman prime minister to be very enthusiastic about a change which equals equality for women in a new area."
Gillard also commented on the unique history of the proposed changes, saying they would forever alter the way in which the Commonwealth operated.
"Just because [the changes] seem straightforward to our modern minds doesn't mean that we should underestimate their historical significance, changing as they will for all time the way in which the monarchy works and changing its history," she said.
The unique nature of the laws surrounding the royal succession means that normal estate planning procedures to not necessarily apply - whereas Australian property settlement agreements take into account the needs of dependants, the monarchy has its own legal obligations.
British prime minister David Cameron said that the new legislation will only apply to the descendants of the Prince of Wales - they will not be applied retroactively.
Cameron told reporters: "The idea that a younger son should become monarch instead of an elder daughter simply because he is a man, or that a future monarch can marry someone of any faith except a Catholic - this way of thinking is at odds with the modern countries that we have become."