He Will Inherit The Duchy Of Cornwall
As the first in line to the throne when Prince Charles becomes king, Prince William is going to earn the title of Duke of Cornwall. As a matter of fact, he has already started to attend duchy meetings. Together with Kate, the two of them will likely be called the Prince and Princess of Wale too.
The Plans For This Transition
In 2018, Charlie Proctor of Royal Central shared that plans are underway for the transition. When he spoke to the Daily Star, he said, “As per tradition, when Prince Charles does take to the throne, William and Kate will become the Prince and Princess of Wales, meaning he will take on additional duties to assist the monarch.” He added, “Just like Prince Charles is preparing to become king, William is already preparing to become Prince of Wales ready for the duties and responsibilities he will have to take on.”