When Prince Harry and Meghan Markle made their bombshell announcement last week, many wondered what their withdrawal from the royal family could mean for their son, Archie Harrison. Prince Harry and Meghan stepping back from their royal duties has raised interesting questions about Baby Archie’s custody, especially since many believe that making sure their son was out of British shores at the time of their announcement was their way of ensuring that the royal family could not get custody of him despite their exit.

However, there’s a provision baked into British law that suggests Prince Charles could have full custody of Baby Archie when he becomes King. Called The Grand Opinion for the Prerogative Concerning the Royal Family, this provision states that the ruling monarch will have automatic custody of all the minor grandchildren.

Currently, this royal right is not valid since the prerogative is not an Act of Parliament and since Queen Elizabeth is Baby Archie’s great-grandmother. When Prince Charles reigns as king, however, the provision can take effect since he is Baby Archie’s grandfather.

Since the provision is based on the principle regarding the ruling sovereign’s right to veto the line of succession of the first six heirs to the throne, and since Baby Archie falls under the first six heirs when Prince Charles becomes the monarch, it means Prince Charles could very well have custody over Prince Harry and Meghan’s son when his time comes.

Whether or not Meghan’s departure from the U.K. with her family is her means of denying Queen Elizabeth and Prince Charles any contact with Baby Archie remains uncertain, but one thing is for sure: Meghan decamping with Baby Archie on North American soil will only complicate things for her son in the future.

The Grand Opinion for the Prerogative Concerning the Royal Family states that the monarch has control over the education, raising, and marriage of his grandchildren.  It was exactly this same provision that stopped Princess Diana from moving to Australia when she once planned to leave the U.K. But with Prince Harry and Meghan seemingly resolved to raise their son on their own, it looks like Meghan is ready to wage a war against the future monarch just to make sure she takes Archie under her wing.