While Kate Middleton and her husband, Prince William have three children, Prince George, Princess Charlotte and Prince Louis, technically, they don't have legal custody of them, based on a 300-year-old rule by King George I, which put the ruling monarch in charge of all minor grandchildren.
AOL shared the details based on the research of Marlene Koenig of Royal Musings.
"The sovereign has legal custody of the minor grandchildren."This law was passed in 1717, according to Koenig, based on his lacking relationship with his son, and the idea that he questioned his decision making.
"This goes back to King George I [who ruled in the early 1700s], and the law's never been changed. He did it because he had a very poor relationship with his son, the future King George II, so they had this law passed that meant the King was the guardian of his grandchildren."While King George didn't have great-grandchildren at that time, it is assumed that they are included in this rule. This means that Queen Elizabeth was in charge of Prince William and Prince Harry until both royals turned 18, and she would have given permission for them to travel.
While it hasn't been confirmed that this is the situation with the great-grandchildren, it is likely that her grandchildren speak with her before making life decisions.In this situation, custody means that the Queen has the final decision in their education and the care, including ordering "the place of their abode, approving nannies and the care and approbation of their marriages."
When Prince Harry and Prince William were young, Prince Charles used to have to ask Her Majesty for permission to fly them out to Scotland with him. When Princess Diana was still alive, in one situation, the Queen did not grant permission when Princess Diana asked to bring her sons to Australia just before her death.
"Technically, they needed permission for travel. The Queen has the last word on parenting decisions like that," explained Koenig.
The wording of this law explains why there were no custody provisions in the divorces of Prince Charles and Princess Diana, and Prince Andrew and Sarah Ferguson (parents of Princess Beatrice and Princess Eugenie), because ultimate custody belonged to Queen Elizabeth.
It will be interesting to see if Prince Harry and Meghan Markle travel with their son, Archie Harrison Mountbatten-Windsor, when they are back on the royal schedule, as the queen will no doubt have a say in that decision.