Reposting the birth announcement from the @SussexRoyal Instagram account, Prince William and Duchess Kate wrote from their @KensingtonRoyal account, "The Duke and Duchess of Cambridge are delighted with the news of the birth of The Duke and Duchess of Sussex's son today, and look forward to meeting the latest addition to the family."
The kind words came after months of reported royal in-fighting among the couples.
Insiders claimed that Prince William, 36, expressed concerns about how fast Prince Harry, 34, and now-Duchess Meghan, 37, moved in their relationship when they first began dating.
Prince Harry reportedly took the brotherly advice personally, leading to tension between the couples.
"William wanted to make sure that Harry was making the right decision,” royal expert Katie Nicholl previously told Fox News. “And I think what was intended as well-meaning, brotherly concern and a bit of advice went down quite badly with Harry, who felt that William wasn’t being as supportive as he might’ve been. So there has certainly been tensions between the brothers.”
“William and Harry, we know the press reports and it is true, they’re not getting along at the moment,” explained Bullen. “But I believe that will resort itself. The move from Kensington Palace to Windsor puts a little distance between the two households. And that will begin to repair the story. And from what I’m being told, Kate Middleton and Meghan actually get on OK. It isn’t about a battle between duchesses. It is much more about the boys. I think hopefully these two mothers will be able to bond more over their children. And I think babies are often a great way to bring families close together.”
Fox News' Stephanie Nolasco contributed to this report.