For Prince William and Princess Kate, they've not only been tested with multiple family health battles, but they've faced an unrelenting series of other personal and public challenges over the past five years.

Kate Middleton's cancer diagnosis was just one challenge she and Prince William had to face together in recent years.

That would be huge if the 6-year-old went on a royal tour. It’s something his siblings, his cousin Prince Archie, his dad, and his Uncle Prince Harry all did as babies, so doing so at 6 (or 7) years old is quite groundbreaking — even for the adorably cheeky, tradition-breaking royal.