So, what does Kate think of the title change? A royal source said the 40-year-old "appreciates the history associated with this role, but will understandably want to look to the future as she creates her own path."
"The Prince and Princess of Wales will approach their roles in the modest and humble way they've approached their work previously," the royal source said, adding that the couple are also "focused on deepening the trust and respect of the people of Wales over time."
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"With Catherine beside him, our new Prince and Princess of Wales will, I know, continue to inspire and lead our national conversations," he added, "helping to bring the marginal to the center ground where vital help can be given."